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Sample records for acrylic acid

  1. Acrylic Acid and Esters Will Be Oversupply

    Zheng Chengwang

    2007-01-01

    @@ Drastic capacity growth The production capacity of acrylic acid in China has grown drastically in recent years. With the completion of the 80 thousand t/a acrylic acid and 130 thous and t/a acrylic ester project in Shenyang Paraffin Chemical Industrial Co., Ltd., (CCR2006,No. 31) the capacity of acrylic acid in China has reached 882 thousand t/a.

  2. 21 CFR 573.120 - Acrylamide-acrylic acid resin.

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Acrylamide-acrylic acid resin. 573.120 Section 573... Food Additive Listing § 573.120 Acrylamide-acrylic acid resin. Acrylamide-acrylic acid resin... acrylamide with partial hydrolysis, or by copolymerization of acrylamide and acrylic acid with the...

  3. Radiochemical coupling of acrylic acid to polyvinylchloride

    Acrylic acid was coupled radiochemically to the surface of polyvinylchloride (PVC) foils. A 500 keV electron generator served as radiation source. After neutralization with ammonia, the surface of the PVC foils got hydrophilic properties. Their capacity of water uptake increased from 0,04 mg/cm2 to about 0,5 mg/cm2 and the condensation of water takes place in form of a clear transparent film and not in form of light scattering droplets. 6 refs., 20 figs., 8 tabs

  4. Radiation-induced graft copolymerization of methyl acrylate and acrylic acid onto rubber wood fiber

    Graft copolymerization of methyl acrylate and acrylic acid monomers onto rubber wood fiber (RWF) was carried out by simultaneous radiation-induced technique. The parameters affecting the grafting reaction were investigated and the optimum conditions for both monomers obtained are as follows: impregnation time = 16 hours, total dose = 30 kGy, methanol : water ratio, 3:1, monomers concentration = 40 v/v % and sulphuric acid concentration = 0.1 mol/L. Fourier Transform Infrared (FTIR), thermogravimetry analysis (TGA), and scanning electron microscope (SEM) analyses used to characterize graft copolymers. The structural investigation by x-ray diffraction (XRD) shows the degree of crystallinity of rubber wood fiber decreased with the incorporation of poly(methyl acrylate) and poly(acrylic acid) grafts. (Author)

  5. Radiation induced grafting of acrylic acid onto extruded polystyrene surface

    Polystyrene materials with good solubility in liquid scintillation cocktails are used to wipe off different types of surfaces in order to determine the tritium removable contamination with the help of a liquid scintillation counter. This paper analyses hydrophilic surface modifications by radiation induced grafting of acrylic groups onto extruded polystyrene plates. Two grafting methods were used: (a) exposure of extruded polystyrene plates, immersed in aqueous acrylic acid solution, to a gamma radiation of a Co-60 source, and (b) exposure of extruded polystyrene plates to a Co-60 source, followed by the immersion of extruded polystyrene plates in aqueous acrylic acid solution. The grafting of acrylic was proved by IR spectrometry and by radiometric methods using acrylic acid labelled with tritium. - Highlights: ► Polystyrene (PS) is used to determine the removable surface contamination (RSC). ► RSC factor may be increased by PS surface modification. ► PS surface was modified by acrylic acid grafting using γ radiation 60Co source. ► Acrylic fragments insertion was determined by IR, and radiometric. ► Grafted PS discs increase RSC factor in the case of tritium contamination.

  6. Rare linking hydrogels based on acrylic acid and carbohydrate esters

    U. Akhmedov

    2012-09-01

    Full Text Available The process of copolymerization of acrylic acid and esters poliallil sucrose; pentaerythritol and sorbitol, some of its laws are identified. The kinetic regularities of copolymerization and the optimum conditions of synthesis was established.

  7. Antimicrobial activity of poly(acrylic acid) block copolymers

    Gratzl, Günther, E-mail: guenther.gratzl@jku.at [Johannes Kepler University Linz, Institute for Chemical Technology of Organic Materials, Altenberger Str. 69, 4040 Linz (Austria); Paulik, Christian [Johannes Kepler University Linz, Institute for Chemical Technology of Organic Materials, Altenberger Str. 69, 4040 Linz (Austria); Hild, Sabine [Johannes Kepler University Linz, Institute of Polymer Science, Altenberger Str. 69, 4040 Linz (Austria); Guggenbichler, Josef P.; Lackner, Maximilian [AMiSTec GmbH and Co. KG, Leitweg 13, 6345 Kössen, Tirol (Austria)

    2014-05-01

    The increasing number of antibiotic-resistant bacterial strains has developed into a major health problem. In particular, biofilms are the main reason for hospital-acquired infections and diseases. Once formed, biofilms are difficult to remove as they have specific defense mechanisms against antimicrobial agents. Antimicrobial surfaces must therefore kill or repel bacteria before they can settle to form a biofilm. In this study, we describe that poly(acrylic acid) (PAA) containing diblock copolymers can kill bacteria and prevent from biofilm formation. The PAA diblock copolymers with poly(styrene) and poly(methyl methacrylate) were synthesized via anionic polymerization of tert-butyl acrylate with styrene or methyl methacrylate and subsequent acid-catalyzed hydrolysis of the tert-butyl ester. The copolymers were characterized via nuclear magnetic resonance spectroscopy (NMR), size-exclusion chromatography (SEC), Fourier transform infrared spectroscopy (FTIR), elemental analysis, and acid–base titrations. Copolymer films with a variety of acrylic acid contents were produced by solvent casting, characterized by atomic force microscopy (AFM) and tested for their antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. The antimicrobial activity of the acidic diblock copolymers increased with increasing acrylic acid content, independent of the copolymer-partner, the chain length and the nanostructure. - Highlights: • Acrylic acid diblock copolymers are antimicrobially active. • The antimicrobial activity depends on the acrylic acid content in the copolymer. • No salts, metals or other antimicrobial agents are needed.

  8. Antimicrobial activity of poly(acrylic acid) block copolymers

    The increasing number of antibiotic-resistant bacterial strains has developed into a major health problem. In particular, biofilms are the main reason for hospital-acquired infections and diseases. Once formed, biofilms are difficult to remove as they have specific defense mechanisms against antimicrobial agents. Antimicrobial surfaces must therefore kill or repel bacteria before they can settle to form a biofilm. In this study, we describe that poly(acrylic acid) (PAA) containing diblock copolymers can kill bacteria and prevent from biofilm formation. The PAA diblock copolymers with poly(styrene) and poly(methyl methacrylate) were synthesized via anionic polymerization of tert-butyl acrylate with styrene or methyl methacrylate and subsequent acid-catalyzed hydrolysis of the tert-butyl ester. The copolymers were characterized via nuclear magnetic resonance spectroscopy (NMR), size-exclusion chromatography (SEC), Fourier transform infrared spectroscopy (FTIR), elemental analysis, and acid–base titrations. Copolymer films with a variety of acrylic acid contents were produced by solvent casting, characterized by atomic force microscopy (AFM) and tested for their antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. The antimicrobial activity of the acidic diblock copolymers increased with increasing acrylic acid content, independent of the copolymer-partner, the chain length and the nanostructure. - Highlights: • Acrylic acid diblock copolymers are antimicrobially active. • The antimicrobial activity depends on the acrylic acid content in the copolymer. • No salts, metals or other antimicrobial agents are needed

  9. Textile dyestuff adsorption by polysaccharide-g-acrylic acid

    Aimed of this study to determine the ability of polysacharide of banana peel as an adsorbent of textile dyes (Maxilon Yellow) before and after the grafting process. The grafting copolymerization process was done by using acrylic acid as monomer, then irradiated by gamma rays as initiator. Parameters observed were adsorption ability of dye, soaking time with KOH, acrylic acid concentration, irradiation dose and resistance to acids. The results showed the optimum absorption obtained at the time of KOH immersion for 3 hours, the concentration of acrylic acid by 20% and the irradiation dose of 30 kGy. Adsorption percentage of polysacharide to Maxilon Yellow after grafting increased by 18,48% compared to before grafting. Resistance to the acid test increased significantly. The results of this study are expected to overcome the problems of waste dyes in the textile industry. (author)

  10. COMPLEX OXIDE CATALYSTS OF ACRYLIC ACID OBTAINING BY ALDOL CONDENSATION METHOD

    Nebesnyi, R.

    2015-01-01

    The present work is dedicated to solving the problem of diversification of the raw materials base for acrylate monomers obtaining,  first of all acrylic acid. Acrylic acid and its derivatives are bulk products of organic synthesis with a wide range of applications. The main industrial method of acrylic acid production is  propylene oxidation. But this method has instable economic indicators as propylene is petroleum origin raw material.It is possible to expand the resource base of acrylic aci...

  11. Decarboxylation-based traceless linking with aroyl acrylic acids

    Nielsen, John

    1998-01-01

    beta-Keto carboxylic acids are known to decarboxylate readily. In our pursuit to synthesize beta-indolinyl propiophenones, we have exploited this chemistry as a mean of establishing a traceless handle. 2-Aroyl acrylic acids have been esterified to a trityl resin, after which Michael-type addition...

  12. 21 CFR 176.110 - Acrylamide-acrylic acid resins.

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylamide-acrylic acid resins. 176.110 Section 176.110 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: PAPER AND PAPERBOARD COMPONENTS Substances for Use Only as Components of Paper...

  13. Use of Acrylic Acid Sodium Acrylate Polymer to Maintain Cocoa Seed Viability

    Pudji Rahardjo

    2010-08-01

    Full Text Available The main problem of cocoa seed storage is moisture content of the seeds because cocoa seeds will germinate if cocoa seeds moisture content is high. The objective of this research is to maintain the cocoa seeds viability in storage using acrylic acid sodium acrylate polymer (AASAP. The function of AASAP is to absorb humidity in storage due to their ability to retain water and to prevent water loss. The experiment was conducted in a laboratory of Indonesian Coffee and Cocoa Research Institute and in Kaliwining Experimental Garden. This experiment was arranged by factorial randomized complete design, in wich AASAP dosages 0%; 0.1% (0.1 g/100 seeds; 0.2% (0.2 g/100 seeds, 0.3% (0.3 g/100 seeds, 0,4% (0,4g/100 seeds, combined with seeds storage period 1, 2, 3 and 4 weeks. The experiment used 3 replications and each repli cation used 100 seeds. Parameter of observation consisted of percentage of seeds germinated in storage, percentage of seeds infected by fungi in storage, seeds moisture content, percentage of seeds germination after storage, and early growth of cocoa seedlings. The results of the experiment showed that AASAP application with some dosages cocoa seeds storage cause to germinate in storage during 2 weeks. AASAP application with some dosages in cocoa seeds storage for 2 weeks would not result in infection by fungi and did not significantly affect seed germination after storage for 1, 2 and 4 weeks, and percentage of germination of cocoa seed after storage for 3 weeks decreased with increase dosage of AASAP. Higher dosage of AASAP would reduce early growth of cocoa seedling. Key words : Theobroma cacao, seed, acrylic acid sodium acrylate, seed storage, viabilty.

  14. Radioinduced grafting of acrylic acid on expanded polystyrene matrices

    The unfixed surface radioactive contamination for low energy β radionuclides (3H and 14C) is determined by wiping the checked surfaces with sponge of absorbent materials. The activity built up by this sponge is measured by a liquid scintillator spectrometer. In this work, a method of obtaining sponges of expanded polystyrene with hydrophobic surface by radioinduced grafting of the acrylic acid is presented. These sponges have diameters of 28 mm, thicknesses of 1.5 - 2 mm and density of 22 mg/cm3. The samples were immersed in a grafting solution with the following composition: acrylic acid 30%, Cu SO4 1%; water 69% which were deeply impregnated in repeated operations under vacuum and pressure conditions, respectively. Finally, the samples were exposed to γ radiation emitted by a 60Co source (IETI 10 000 - IFIN-HH). The dose rates were 0.3, 0.5 and 1 Mrad/h. The range of the absorbed doses was 1 - 25 Mrad. The yields of radiochemical grafting have been determined by gravimetric, spectrophotometric and radiometric methods. The grafting agent used was 3H labelled acrylic acid. The solvation capacity and the quenching characteristics of the grafted sponges in liquid scintillators, as well as the sampling yields have been analyzed as function of irradiation procedure and the percentage of grafted acrylic fragments. The superficial grafting of the acrylic acid has been carried out by the mentioned technique, leading to the increase of the wiping efficiency of the unfixed surface contaminating activity, without changes of polymer solubility in liquid scintillators and without the perturbation of the radioactivity detection process. (authors)

  15. Acrylic acid obtaining from methanol and acetic acid in the presence of complex oxide catalysts

    Небесний, Роман Володимирович; Піх, Зорян Григорович; Шпирка, Ірина Іванівна; Івасів, Володимир Васильович; Небесна, Юлія Віталіївна; Фуч, Уляна Василівна

    2015-01-01

    The purpose of this work is to research process of single-stage acrylic acid obtaining from methanol and acetic acid, namely: to develop effective catalysts for the process of methanol oxidation to formaldehyde with its further aldol condensation with acetic acid to acrylic acid, and to determine optimum conditions for the process. Complex oxide catalysts consisting of oxides of boron, phosphorus, tungsten and vanadium supported on the silica gel have been investigated. The effect of vanadium...

  16. Scientific Opinion on the safety evaluation of the active substance, acrylic acid, sodium salt, co-polymer with acrylic acid, methyl ester, methacrylic acid, 2 hydroxypropylester, and acrylic acid cross-linked for use in active food contact materials

    EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF

    2013-04-01

    Full Text Available This scientific opinion of the EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids deals with the safety evaluation of the acrylic acid, sodium salt, co-polymer with acrylic acid, methyl ester, methacrylic acid, 2 hydroxypropylester, and acrylic acid cross-linked (CAS No. 117675-55-5, FCM Substance No 1022, to be used as liquid absorber in the form of fibres in absorbent pads for the packaging of fresh or frozen meat, poultry, and fish as well as fresh fruits and vegetables. The Panel considered that migration is not expected when the absorption capacity of the pads is not exceeded. Therefore no exposure from the consumption of the packed food is expected. The Panel also considered that none of these starting substances and the cross-linked polymer gives rise to concern for genotoxicity. Therefore the CEF Panel concluded that the use of the substance acrylic acid, sodium salt, co-polymer with acrylic acid, methyl ester, methacrylic acid, 2 hydroxypropylester, and acrylic acid cross-linked does not raise a safety concern when used as fibres in absorber pads for the packaging of fresh or frozen meat, poultry, fish, fruits and vegetables under conditions under which the absorption capacity of the pads is not exceeded and mechanical release of the fibres from the pads is excluded.

  17. A New Process for Acrylic Acid Synthesis by Fermentative Process

    Lunelli, B. H.; Duarte, E. R.; de Toledo, E. C. Vasco; Wolf Maciel, M. R.; Maciel Filho, R.

    With the synthesis of chemical products through biotechnological processes, it is possible to discover and to explore innumerable routes that can be used to obtain products of high addes value. Each route may have particular advantages in obtaining a desired product, compared with others, especially in terms of yield, productivity, easiness to separate the product, economy, and environmental impact. The purpose of this work is the development of a deterministic model for the biochemical synthesis of acrylic acid in order to explore an alternative process. The model is built-up with the tubular reactor equations together with the kinetic representation based on the structured model. The proposed process makes possible to obtain acrylic acid continuously from the sugar cane fermentation.

  18. Surface cross-linked humic acid - polysodium acrylate superabsorbent

    Chu, M.; Zhu, S.; Li, H.; Huang, Z.; Zhang, X. [China University of Mining and Technology, Beijing (China)

    2005-03-01

    A novel composite super-absorbent of humic acid-polysodium acrylate was invented by surface cross-linking reaction of lignite humic acid and poly. Humic acid was abstracted from leonardite and poly was synthesized by solution polymerization. Water absorbing mechanism of composite superabsorbent was explored based on FTIR and SEM. The effect of surface cross-linking reaction conditions, such as the ratio of methanol to water, cross-linking agent concentration, and the amount of humic acid on water absorbing were investigated. Experiments show that the water absorbency of superabsorbent can be greatly improved by humic acid. When the mass fraction of humic acid is 10%, the ratio of cross-linking agent to PSA is 0.2%, and the ratio of methanol to water is 1.8, the water absorbency is the best: 750 g/g for deionied water and 260 g/g for running. water. 9 refs., 5 figs., 1 tab.

  19. Conformational Transition of Poly (Acrylic Acid) Detected by Microcantilever Sensing

    LI Kai; LIU Hong; ZHANG Qing-Chuan; XUE Chang-Guo; WU Xiao-Ping

    2007-01-01

    Poly (acrylic acid) (PAA) chains are grafted on one side of a microcantilever by the self-assembled method and the deflections of the microcantilever are detected as a function of medium pH from 3 to 11. It is found that when the pH varies, the microcantilever deflects because of the changing surface stress. By analysing the electrostatic repulsive effect, the surface stress change is related to the conformation transition of PAA from a collapse state to a swelling state. This method offers the interaction information among the polymer chains during the conformational transition and affords an alternative way to study conformational change of polymers.

  20. Swelling Behaviors of Polyaniline-Poly(Acrylic Acid) Hydrogels

    ZHANG You-wei; ZHAO Jiong-xin; LI Xiao-feng; TAO Yong; WU Cheng-xun

    2005-01-01

    Using poly(acrylic acid) (PAA) aqueous solution, NaOH aqueous solution, aniline(An) and ammonim persulfate(APS), PAn-PAA hydrogels with a semi-interpenetrating structure connected by physical interlocks, chemical ion bonds and hydrogen bonds wcre prepared. The swelling properties of the hydrogels in solutions of different pH values(adjusted by adding NaOH or HCl) were studied. All the hydrogels prepared have similar swelling curves (the curves of equilibrium swelling ratio vs. pH value) and reach their maximum swelling at pH of 8 - 10. The maximum swelling ratio of the hydrogels is dependent on composition, including molecular weight of PAA, polymer content of the hydrogel,and molar ratios of AA to An, APS to An, and NaOH to AA.And the compositional dependence of the swelling capacity of PAn-PAA hydrogels was also studied.

  1. New initiation system for polymerization of acryl acid

    LI Hai-pu; ZHONG Hong; CHEN Qi-yuan; YIN Zhou-lan

    2005-01-01

    The redox initiation system for polyacrylate sodium of high molecular mass was designed and its effect with varying component dosage on the degree of polymerization was investigated. The results show that the proper type and amount of inorganic salt, as well as amine initiator, are conductive to the increase of degree of polymerization. The fine ingredient of the initiation system is as follows:the dosages of amine, persulphate and inorganic salt are 0.75%, 0.10% and 1.00% by mass based on acryl acid respectively, the molar ratio of sulphite to the persulphate is 1:1. Under such conditions the degree of polyacrylate can reach 7.43×107 with a acceptable polymerization time for industrial production.

  2. Study on preirradiation grafting of acrylic acid to cotton cellulose

    Grafting copolymerization of acrylic acid to cotton cellulose by using pre-irradiating method was investigated. At lower concentration of monomer (10%) the relationship between grafting yield and total dose, dose rate, reaction time and reaction temperature was measured. It was found that in the temperature range of 294 K to 323 K the grafting yield decreased with increasing of grafting reaction temperature. The grafting yields as a function of above reaction conditions were given by the expression Gr% = 5.9 x 10-10De20.27/RT(1-e-0.313te-6.87/RT), where R 8.314 x 10-3kj·K-1·mol-1, D = irradiation dose, T = reaction temperature, and t = reaction time

  3. Polymerisation by acrylamide and acrylic acid inverse suspension

    Sergio Alejandro LLoreda Blanco

    2010-04-01

    Full Text Available This work describes polymerisation by inverse suspension of acrylamide monomers and acrylic acid for forming homopolymers or copolymers This type of polymersitaion's advantages are described and reasons given for why it should be studied. The article stresses the importance of these types of monomer for obtaining materials presenting great affinity for water, such as super-absorbents and controlled liberation mechanism. Important aspects are presented such as type of initiation, monomer composition and continuous phase composition; parameters are described offering an important basis for formulating a system leading to successfully obtaining the desired materials' most relevant characteristics such as particle distribution and size polymerisation kinetics, conversion and water absorption capacity respecting the system's modifiable parameters. The foregoing is important since the product can be modified, bestowing propierties on it which are suitable for its use.

  4. Copolymerization of Indene with Acrylic Acid, Itaconic Acid and Acrylonitrile: Characterization and Reactivity Ratios

    Random copolymers of indene (In) with acrylic acid (AA), itaconic acid (IA) and acrylonitrile (AN) were synthesized by free radical polymerization in dioxane in the presence of azobisisobutyronitrile as an initiator at 60 degree C. The homopolymer of indene and acrylonitrile was prepared using K2MnO4 and sulphuric acid as an initiator, while acrylic acid and itaconic acid were prepared using K2S2O8 solution. The reactivity ratios of the monomers were calculated by different methods. X-ray diffraction as well as thermal analyses were studied. The latter was studied via thermogravimetric analysis and differential thermal analysis. The complexation with metal ions such as Cu+2 and Fe+2 was investigated. The copolymerization and the complexation processes were confirmed by FTIR spectroscopy. Also the activation energy of the prepared copolymers was determined

  5. Synthesis of poly(N-isopropylacrylamide-co-acrylic acid) model compounds for filtration experiments

    Hinge, Mogens; Christensen, Morten Lykkegaard; Scales, Peter;

    2005-01-01

    microgels. Capillary rheometry indicates that the blocks of poly(acrylic acid) are placed on the surface of the microgels. The combination of these three results reveal that the microgels have a core mainly consisting of poly(N-isopropylacrylamide) and a diffuse/cloudy surface consisting mainly of poly(acrylic...

  6. Blends of dissolved cellulose with acrylic acid copolymers or microfibrillated cellulose

    Saarikoski, Eve

    2015-01-01

    The aim of the thesis was to develop dissolved cellulose (dissolved in NaOH/ZnO) based blends with acrylic acid copolymers (poly(ethylene-co-acrylic acid) (PE-co-AA) or poly(acrylamide-co-acrylic acid) (PAA-co-AA)) or microfibrillated cellulose (MFC) in the way they could be used in injection molding or for film/coating applications. This thesis summarizes the research reported in five publications supported by some unpublished results. Rheological studies done in the contexts of this work...

  7. Catalytic routes towards acrylic acid, adipic acid and epsilon-caprolactam starting from biorenewables

    Beerthuis, R.; Rothenberg, G.; Shiju, N.R.

    2015-01-01

    The majority of bulk chemicals are derived from crude oil, but the move to biorenewable resources is gaining both societal and commercial interest. Reviewing this transition, we first summarise the types of today's biomass sources and their economical relevance. Then, we assess the biobased productions of three important bulk chemicals: acrylic acid, adipic acid and epsilon-caprolactam. These are the key monomers for high-end polymers (polyacrylates, nylon 6.6 and nylon 6, respectively) and a...

  8. Poly (ethylene oxide)-block-poly (n-butyl acrylate)-blockpoly (acrylic acid) triblock terpolymers with highly asymmetric hydrophilic blocks: synthesis and aqueous solution properties

    Petrov, P; Yoncheva, K. (Krassimira); Mokreva, P. (Pavlina); Konstantinov, S.; J M Irache; Müller, A.H.E. (Axel H.E.)

    2013-01-01

    The synthesis and aggregation behaviour in aqueous media of novel amphiphilic poly(ethylene oxide)- block-poly(n-butyl acrylate)-block-poly(acrylic acid) (PEO–PnBA–PAA) triblock terpolymers were studied. Terpolymers composed of two highly asymmetric hydrophilic PEO (113 monomer units) and PAA (10–17 units) blocks, and a longer soft hydrophobic PnBA block (163 or 223 units) were synthesized by atom transfer radical polymerisation (ATRP) of n-butyl acrylate and tert-butyl acrylate ...

  9. CATALYTIC HYDROGENATION OF ACRYLATE ASMMETRIC Dd(Ⅱ)—CHELATING RESINS CONTAINING AMINO ACID LIGANDS

    Wangying; WangHongzuo; 等

    1995-01-01

    The catalytic hydrogenation of palladium chelating resins containing chiral amino acid ligands based on lower crosslinked poly(chloroethyl acrylate) and some effects on the rate of hydrogenation were studied.

  10. FT-RAMAN SPECTROSCOPY FOR MONITORING THE POLYMERIZATION OF ACRYLIC ACID IN AQUEOUS SOLUTION

    Jiang Yu; Hui-zhou Liu; Jia-yong Chen

    1999-01-01

    FT-Raman spectroscopy was used to monitor the polymerization of acrylic acid in aqueous solution. A simple method to avoid the noise in the background during the signal processing via Fourier transformation was used in this work. The effects of the amount of initiator used on the polymerization are studied. When the amount of the initiator in the polymerization was increased, both the rate and extent of polymerization of acrylic acid will be increased.

  11. Synthesis and Properties of IPN Hydrogels Based on Konjac Glucomannan and Poly(acrylic acid)

    Bing LIU; Zhi Lan LIU; Ren Xi ZHUO

    2006-01-01

    Novel interpenetrating polymer network (IPN) hydrogels based on konjac glucomannan (KGM) and poly(acrylic acid) (PAA) were prepared by polymerization and cross-linking of acrylic acid (AA) in the pre-fabricated KGM gel. The IPN gel was analyzed by FT-IR. The studies on the equilibrium swelling ratio of IPN hydrogels revealed their sensitive response to environmental pH value. The results of in vitro degradation showed that the IPN hydrogels retain the enzymatic degradation character of KGM.

  12. Radiation grafting of acrylic acid onto polypropylene films

    A study has been made for the preparation of membranes by the direct radiation grafting of acrylic acid (AAc) onto polypropylene (PP) films. The appropriate reaction conditions were selected under which the graft polymerization was carried out successfully. The effect of different solvents such as benzene, methanol/water mixture, isopropanol/water mixture, dimethyl formamide and distilled water on the swelling and grafting process of AAc onto PP films was investigated. In this grafting system ammonium ferrous sulphate (Mohr's salt) and ferric chloride were used as inhibitors to minimize the homopolymerisation of AAc and the suitable concentration of the inhibitor was found to be 1.0 and 1.5 wt% for Mohr's salt and ferric chloride, respectively. Also, the effect of monomer concentration on the rate of grafting was investigated. The dependence of the grafting rate on monomer concentration was found to be 1.1 order. This grafting system proceeded by diffusion controlled process. Some selected properties of the grafted films such as swelling behaviour, gel determination, mechanical and electrical properties were also investigated. It was found that the grafted membranes possess good hydrophilic properties which may make them promising in some practical applications. (author)

  13. Characterization of Functionalized Acrylic acid /4- Vinyl Pyridine Graft Copolymers

    Properties and characterization of the membranes prepared by radiation grafting of acrylic acid (AAc) or/ and 4-vinyl pyridine (4VP) onto low density polyethylene (LDPE) and polypropylene (PP) films were carried out. The FTIR spectra for the grafted membranes were studied to evaluate the structure change as a result of grafting. The swelling behaviour of the graft copolymer in methanol was studied. It was found that the grafting of AAc and/ or 4- VP onto LDPE and PP resulted in introducing good hydrophilic properties to such polymer substrates. The hydrophilic properties were directly proportional to the amount of functional groups. The mechanical properties (Young's modulus, elongation percent and tensile strength) of the grafted membranes also, have been investigated. As the grafting degree increases, the modulus also increases. Increasing the hydrophilicity of the membranes by chemical treatment enhances its mechanical properties. The thermal parameters of the grafted membranes such as δHm1. δHm2, and Trc have been also studied by using DSC

  14. Interaction of photosensitive surfactant with DNA and poly acrylic acid

    Zakrevskyy, Yuriy, E-mail: yuriy.zakrevskyy@fh-koeln.de; Paasche, Jens; Lomadze, Nino; Santer, Svetlana, E-mail: santer@uni-potsdam.de [Experimental Physics, Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str. 24-25, D-14476 Potsdam (Germany); Cywinski, Piotr; Cywinska, Magdalena; Reich, Oliver; Löhmannsröben, Hans-Gerd [Physical Chemistry, Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, D-14476 Potsdam (Germany)

    2014-01-28

    In this paper, we investigate interactions and phase transitions in polyelectrolyte-surfactant complexes formed between a cationic azobenzene-containing surfactant and two types of polyelectrolytes: natural (DNA) or synthetic (PAA: poly acrylic acid). The construction of a phase diagram allowed distancing between four major phases: extended coil conformation, colloidally stable compacted globules, colloidal instability range, and surfactant-stabilized compact state. Investigation on the complexes’ properties in different phases and under irradiation with UV light provides information about the role of the surfactant's hydrophobic trans isomers both in the formation and destruction of DNA and PAA globules as well as in their colloidal stabilization. The trans isomer shows much stronger affinity to the polyelectrolytes than the hydrophilic cis counterpart. There is no need for complete compensation of the polyelectrolyte charges to reach the complete compaction. On contrary to the findings previously reported in the literature, we demonstrate – for the first time – complete polyelectrolyte compaction which occurs already at 20% of DNA (and at 50% of PAA) charge compensation. The trans isomer plays the main role in the compaction. The aggregation between azobenzene units in the photosensitive surfactant is a driving force of this process. The decompaction can be realized during UV light irradiation and is strongly influenced by the interplay between surfactant-surfactant and surfactant-DNA interactions in the compacted globules.

  15. Interaction of photosensitive surfactant with DNA and poly acrylic acid

    In this paper, we investigate interactions and phase transitions in polyelectrolyte-surfactant complexes formed between a cationic azobenzene-containing surfactant and two types of polyelectrolytes: natural (DNA) or synthetic (PAA: poly acrylic acid). The construction of a phase diagram allowed distancing between four major phases: extended coil conformation, colloidally stable compacted globules, colloidal instability range, and surfactant-stabilized compact state. Investigation on the complexes’ properties in different phases and under irradiation with UV light provides information about the role of the surfactant's hydrophobic trans isomers both in the formation and destruction of DNA and PAA globules as well as in their colloidal stabilization. The trans isomer shows much stronger affinity to the polyelectrolytes than the hydrophilic cis counterpart. There is no need for complete compensation of the polyelectrolyte charges to reach the complete compaction. On contrary to the findings previously reported in the literature, we demonstrate – for the first time – complete polyelectrolyte compaction which occurs already at 20% of DNA (and at 50% of PAA) charge compensation. The trans isomer plays the main role in the compaction. The aggregation between azobenzene units in the photosensitive surfactant is a driving force of this process. The decompaction can be realized during UV light irradiation and is strongly influenced by the interplay between surfactant-surfactant and surfactant-DNA interactions in the compacted globules

  16. Radiation-induced grafting of acrylic acid onto polypropylene film and its biodegradability

    Mandal, Dev K.; Bhunia, Haripada; Bajpai, Pramod K.; Chaudhari, C. V.; Dubey, K. A.; Varshney, L.

    2016-06-01

    Polypropylene based commodity polyolefins are widely used in packaging, manufacturing, electrical, pharmaceutical and other applications. The aim of the present work is to study the effect of grafting of acrylic acid on the biodegradability of acrylic acid grafted polypropylene. The effect of different conditions showed that grafting percentage increased with increase in monomer concentration, radiation dose and inhibitor concentration but decreased with increase in radiation dose rate. The maximum grafting of 159.4% could be achieved at optimum conditions. The structure of grafted polypropylene films at different degree of grafting was characterized by EDS, FTIR, TGA, DSC, SEM and XRD. EDS studies showed that the increase in acrylic acid grafting percentage increased the hydrophilicity of the grafted films. FTIR studies indicated the presence of acrylic acid on the surface of polypropylene film. TGA studies revealed that thermal stability decreased with increase in grafting percentage. DSC studies showed that melting temperature and crystallinity of the grafted polypropylene films lower than polypropylene film. SEM studies indicated that increase in acrylic acid grafting percentage increased the wrinkles in the grafted films. The maximum biodegradability could be achieved to 6.85% for 90.5% grafting. This suggested that microorganisms present in the compost could biodegrade acrylic acid grafted polypropylene.

  17. Synthesis and characterization of cashew gum/acrylic acid nanoparticles

    Silva, Durcilene A. da; Feitosa, Judith P.A. [Departamento de Quimica Organica e Inorganica, Universidade Federal do Ceara - C. Postal 6021, 60.455-760, Fortaleza, CE (Brazil); Paula, Haroldo C.B. [Departamento de Quimica Analitica e Fisico-Quimica, Universidade Federal do Ceara - C. Postal 6021, 60.455-760, Fortaleza, CE (Brazil); Paula, Regina C.M. de [Departamento de Quimica Organica e Inorganica, Universidade Federal do Ceara - C. Postal 6021, 60.455-760, Fortaleza, CE (Brazil)], E-mail: rpaula@dqoi.ufc.br

    2009-03-01

    This paper describes the preparation of nanoparticles from cashew gum (CG) and acrylic acid (AA) by free radical polymerization using cerium (IV) ammonium nitrate (CAN) as an initiator. The yields of the nanoparticles (NP) obtained by varying the R{sub CG/AA} from 0.5 to 2.0 were between 65 and 40%. The FT-IR spectra of the NP samples showed bands characteristic of the cashew gum spectrum and a new band at 1560 cm{sup -1} assigned to the stretching vibration of COO{sup -} groups of polyacrylic acid. On increasing the R{sub CG/AA} from 0.5 to 2.0 an increase in particle size was observed. The NP with an R{sub CG/AA} of 0.5 were smaller and had higher storage stability than the NP with an R{sub CG/AA} of 1.0 or 2.0. The increase in R{sub CG/AA} had no significant effect on the zeta potential of the NP in water. The NP were dried and re-dissolved in water to observe the effect of freeze-drying on particle size. For the NP with an R{sub CG/AA} of 0.5 an increase in particle size was observed from 71 to 402 nm, however, for the NP with an R{sub CG/AA} of 1.0 or 2.0 a small variation in particle diameter was noted. The behavior of the CG/AA NP was also found to be pH sensitive.

  18. Radiation modification of water absorption of cassava starch by acrylic acid/acrylamide

    Graft co polymerizations of acrylamide and/or acrylic acid onto cassava starch by a simultaneous irradiation technique using gamma-rays as the initiator were studied with regard to various parameters of importance: the monomer-to-cassava starch ratio, total dose (kGy), dose rate (kGy h-1), acrylamide-to-acrylic acid ratio, and the addition of nitric acid and maleic acid as the additives. Grafting parameters were determined in relation to the water absorption of the saponified graft copolymer. The water absorption of the saponified graft copolymer in salt and buffer solutions of different ionic strengths was also measured, from which the super absorbent properties are found to be P H sensitive. The starch graft copolymers of acrylamide and acrylic acid give higher water absorption than the starch graft copolymers of either acrylamide or acrylic acid alone. The porosity of the saponified starch graft copolymers prepared by the acrylamide/acrylic acid ratios of 70:30 and 50:50 was much higher than the porosity of copolymers in terms of fine networks. Ionic strength and multi-oxidation states of the saline and buffer solutions markedly decreased the water absorption of the saponified cassava starch grafted super absorbent polymers.

  19. Polymorphism and polymerisation of acrylic and methacrylic acid at high pressure

    Oswald, Iain D. H.; Urquhart, Andrew J.

    2011-01-01

    The polymorphism and polymerisation of two related acids have been investigated under high pressure conditions. Acrylic acid crystallises as a new polymorph at 0.65 GPa whilst methacrylic acid crystallises in a new polymorph at a higher pressure of 1.5 GPa. Both these new polymorphs exhibit similar...

  20. Radiation sensitive acrylate composition

    This application relates to radiation-sensitive compositions and more particularly to such compositions comprising acrylated esters. As used in this specification, the term acrylated esters refers to either acrylic or methacrylic acid resins. 3 tabs

  1. Gold Nanoparticles Protected with Thiol-Derivatized Amphiphilic Poly( -caprolactone)-b-poly(acrylic acid)

    Javakhishvili, Irakli; Hvilsted, Søren

    2008-01-01

    Amphiphilic poly(c-caprolactone)-b-poly(acrylic acid) (HS-PCL-b-PAA) bearing thiol functionality at the PCL terminal has been synthesized by a combination of ring-opening polymerization (ROP) of c-caprolactone (c-CL), esterification of hydroxy chain end with protected mercaptoacetic acid, subsequ......Amphiphilic poly(c-caprolactone)-b-poly(acrylic acid) (HS-PCL-b-PAA) bearing thiol functionality at the PCL terminal has been synthesized by a combination of ring-opening polymerization (ROP) of c-caprolactone (c-CL), esterification of hydroxy chain end with protected mercaptoacetic acid...

  2. Synthesis of acrylic acid derivatives from carbon dioxide and ethylene mediated by molecular nickel complexes

    Lee, Sin Ying Tina

    2013-01-01

    This work aimed at the synthesis of acrylic acid derivatives from ethylene and CO2 and well as the investigation of β-hydride elimination reaction of nickelalactones with methyl iodide and methyl triflate to form methyl acrylate. The oxidative coupling reaction of ethylene and CO2 on nickel center was ligand selective, and gave low yields of nickelalactone product at mild synthetic conditions. Key intermediates identified and characterized in the β-H elimination reaction provided rich insight...

  3. Enzymatic direct synthesis of acrylic acid esters of mono- and disaccharides

    Tsukamoto, Junko; Heabel, Sophie; Valenca, Gustavo P.; Peter, Martin; Franco, Telma

    2010-01-01

    BACKGROUND: There is an increased need to replace materials derived from fossil sources by renewables. Sugar-cane derived carbohydrates are very abundant in Brazil and are the cheapest sugars available in the market, with more than 400 million tons of sugarcane processed in the year 2007. The objective of this work was to study the preparation of sugar acrylates from free sugars and free acrylic acid, thus avoiding the previous preparation of protected sugar derivatives, such as glycosides, o...

  4. Acidic polyanion poly(acrylic acid) prevents calcium oxalate crystal deposition

    Kleinman, Jack G.; Alatalo, Laura J.; Beshensky, Ann M.; Wesson, Jeffrey A.

    2008-01-01

    Acidic macromolecules inhibit calcium oxalate nucleation, growth, aggregation and attachment to cells in vitro. To test for such an effect in vivo we used osmotic minipumps to continuously infuse several doses of the 5.1 kDa poly(acrylic acid) (pAA5.1) into rats fed a diet which causes renal calcium oxalate crystal deposition. Although kidneys of rats receiving the saline control contained calcium oxalate crystals, measured by polarized light microscopy, those of animals given pAA5.1 had sign...

  5. Graft Polymerization of Acrylic Acid on a Polytetrafluoroethylene Panel by an Inductively Coupled Plasma

    Lan, Yan; You, Qingliang; Cheng, Cheng; Zhang, Suzhen; Ni, Guohua; Nagatsu, M.; Meng, Yuedong

    2011-02-01

    Surface modification on a polytetrafluoroethylene (PTFE) panel was performed with sequential nitrogen plasma treatments and surface-initiated polymerization. By introducing COO- groups to the surface of the PTFE panel through grafting polymerization of acrylic acid (AA), a transparent poly (acrylic acid) (PAA) membrane was achieved from acrylic acid solution. Grafting polymerization initiating from the active groups was achieved on the PTFE panel surface after the nitrogen plasma treatment. Utilizing the acrylic acid as monomers, with COO- groups as cross link sites to form reticulation structure, a transparent poly (acrylic acid) membrane with arborescent macromolecular structure was formed on the PTFE panel surface. Analysis methods, such as fourier transform infrared spectroscopy (FTIR), microscopy and X-ray photoelectron spectroscopy (XPS), were utilized to characterize the structures of the macromolecule membrane on the PTFE panel surface. A contact angle measurement was performed to characterize the modified PTFE panels. The surface hydrophilicities of modified PTFE panels were significantly enhanced after the plasma treatment. It was shown that the grafting rate is related to the treating time and the power of plasma.

  6. EB curable coating based on soy-oil fatty acid modified acrylate

    Soy-oil fatty acid was used to synthesize the soy-oil fatty acid modified acrylic coating by esterification reaction. After coating and EB curing, the results showed that the properties of the film were excellent, and it was suitable for the coating of wood furniture cured by EB

  7. Effects of preirradiation graft polymerization of acrylic acid onto polyethylene film

    With the aid of preirradiation method of grafting onto low-density polyethylene film, a systematic investigation was made of grafting of aqueous acrylic acid under conditions such as monomer concentrations, irradiation dose, dose rate, reaction time, the effect of concentrations of Mohr's salt and sulphuric acid on the graft reaction. (author)

  8. Direct Synthesis of Hyperbranched Poly(acrylic acid-co-3-hydroxypropionate

    Efkan Çatıker

    2015-01-01

    Full Text Available Hyperbranched poly(acrylic acid-co-3-hydroxypropionate (PAcHP was synthesized by base-catalyzed hydrogen transfer polymerization of acrylic acid through one step. The copolymers obtained through solution and bulk polymerization were insoluble in water and all organic solvents tried. Structural and compositional characterizations of hyperbranched PAcHP were performed by using FTIR, solid 13C-NMR, TGA, and titrimetric analysis. Acrylate fraction of the hyperbranched PAcHP obtained via bulk polymerization was determined as 60–65% by comparing TGA curves of hyperbranched PAcHP and pure poly(3-hydroxy propionate (PHP. However, analytical titration of the same sample revealed that acrylic acid units were about 47.3%. The results obtained from TGA and analytical titration were used to evaluate the chemical structure of the copolymer. Hyperbranched PAcHP exhibited hydrogel properties. Swelling behavior of the copolymer was investigated at a wide pH range and ionic strength. The dynamic swelling profiles of hyperbranched PAcHP exhibited a fast swelling behavior in the first hour and achieved the equilibrium state within 12 h in PBS. Depending on the conditions, the copolymers exhibited swelling ratios up to 2100%. As the copolymer has easily biodegradable propionate and versatile functional acrylic acid units, it can be used as not only biodegradable material in medical applications but also raw material in personal care commodities.

  9. Preparation and characteristics of acrylic acid/styrene composite plasma polymerized membranes

    Plasma polymerization has gained increasing interest for the deposition of functional plasma-polymerized membranes suitable for a wide range of applications on account of its advantageous features. In this work, acrylic acid/styrene composite plasma polymerized membranes were synthesized by plasma polymerization of a mixture of acrylic acid and styrene monomers in a low-frequency after-glow capacitively coupled plasma (CCP) discharge process. The structure and composition of the plasma polymerized membranes were characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The results showed that the partial pressure ratio between acrylic acid (AA) and styrene (St), applied discharge power and the energy of the extracted particles have considerable effects on the structure and the content of functional groups of the deposited membranes.

  10. Effects of acrylamide and acrylic acid on creatine kinase activity in the rat brain

    In vitro, both acrylamide and acrylic acid inhibited creatine kinase (CK) activity in rat brain homogenates, and acrylic acid was more potent than acrylamide. In vivo, however, when given i.p. 50 mg/kg per day for 8 days to rats, only acrylamide inhibited CK activity in the brain and caused apparent neurological signs. 14C in the brain 24 h after the injection of 14C-labelled chemicals was more than 7 times greater with acrylamide than with acrylic acid. The inhibition of CK activity by acrylamide varied in eight regions of the brain; from 54% in hypothalamus to 27% in cerebellar vermis. The regional difference of CK inhibition, however, did not agree well with either 14C distribution or with the distribution in regions which appear clinically or pathologically vulnerable to acrylamide. (orig.)

  11. Effects of gas atmospheres on poly(lactic acid) film in acrylic acid plasma treatment

    Plasma polymerized acrylic acid (AA) coatings were deposited on poly(lactic acid) (PLA) films in various gas atmospheres during the pre-treatment of PLA and the deposition of AA, respectively. Therefore, this work was twofold: the argon pretreated PLA films followed by a deposition in argon were investigated against the mixture of argon and oxygen pretreated ones under the same deposition conditions; the plasma deposition of AA operating in different atmospheres (argon, oxygen and nitrogen) was employed to modify the pretreated PLA in oxygen. Chemical and physical changes on the plasma-treated surfaces were examined using contact angle, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM) and attenuated total reflection infrared (ATR-FTIR) analysis. The results showed that the discharge gas can have a significant influence on the chemical composition of the PLA surfaces: oxygen plasmas introduced oxygen-containing groups in company with surface etching in pretreatment and deposition, while argon discharges was able to achieve much better hydrophilic behavior and high retention ratio of poly(acrylic acid) (PAA) coating before and after washing in water.

  12. Effects of gas atmospheres on poly(lactic acid) film in acrylic acid plasma treatment

    Zhao, Yun, E-mail: yun.zhaotju@yahoo.com [Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Turin (Italy); Fina, Alberto [Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino – sede di Alessandria, V. T. Michel 5, 15121 Alessandria (Italy); Venturello, Alberto; Geobaldo, Francesco [Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Turin (Italy)

    2013-10-15

    Plasma polymerized acrylic acid (AA) coatings were deposited on poly(lactic acid) (PLA) films in various gas atmospheres during the pre-treatment of PLA and the deposition of AA, respectively. Therefore, this work was twofold: the argon pretreated PLA films followed by a deposition in argon were investigated against the mixture of argon and oxygen pretreated ones under the same deposition conditions; the plasma deposition of AA operating in different atmospheres (argon, oxygen and nitrogen) was employed to modify the pretreated PLA in oxygen. Chemical and physical changes on the plasma-treated surfaces were examined using contact angle, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM) and attenuated total reflection infrared (ATR-FTIR) analysis. The results showed that the discharge gas can have a significant influence on the chemical composition of the PLA surfaces: oxygen plasmas introduced oxygen-containing groups in company with surface etching in pretreatment and deposition, while argon discharges was able to achieve much better hydrophilic behavior and high retention ratio of poly(acrylic acid) (PAA) coating before and after washing in water.

  13. The influence of Copolimers Acrylic Acid onto Poli(Etilene Terephthalate)woven fabric

    To improve suitability of wearing poli etilene terephthalate (PET) wovenfabric, it need to enhance the ability in absorbing of water vapour. For theabove reason acrylic acid (AA) has been grafted onto PET wovenfabric(PET-g-AA). Fourier Transform Infrared (FT-IR) data show that poly(acrylic acid) have grafted onto PET woven fabric. Thermal propertiesobtained from DSC (Differential Scanning Calorimeter) measurements of PET-g-AA show that the grafting does not affect bulk properties of PET. Thedecrease of the tensile strength had occurred to PET-g-MMA, however it ratherinfluenced by the reaction time than the initial concentration of acrylicacid. (author)

  14. Synthesis of Acrylic Acid/Kaoline Powder Superabsorbent Composite by Inverse-suspending Polymerization

    ZHONG Jin-feng; XUE Yi-ming; WU Ji-huai; LIN Jian-ming; WEI Yue-lin

    2004-01-01

    An acrylic acid/kaoline powder superabsorbent composite with a water absorbency of the superabsorbent composite about 1/800 was synthesized by inverse-suspending polymerization reaction between acrylic acid monomer and kaoline ultrafine powder. The influence of the dispersant agent on the configuration of the products in the inverse suspension polymerization is investigated. The influences of the kaoline powder, cross-linker, initiator, neutralization degree and the volume ratio of oil to water phase on the water absorbency of the superabsorbent composites are discussed in the paper.

  15. A study on antithrombogenic polymeric dialytic membrane. Irradiation grafting acrylic acid and styrene into polyethylene films

    A new type of antithrombogenic polymeric dialytic membrane with a hydrophilic-hydrophobic microphase structure was prepared by grafting acrylic acid and styrene into polyethylene films, using peroxidation pre-irradiation technique. Various ratios of monomers influencing on properties of the grafted films were examined. Experimental results showed that the grafted films have superior mechanic strength, and their antithrombogenicity and permeability were 30 and 10 times higher than that of the ungrafted films respectively on condition of the volume ratio 1:1 (styrene vs acrylic acid)

  16. Graft Copolymerization of Acrylic Acid onto Fungal Cell Wall Structural Polysaccharide

    2001-01-01

    Acrylic acid was graft-copolymerized onto Rhi. oryzae's cell wall structural polysacchaxide directly and efficiently in aqueous solution with ceric ammonium nitrate as initiator. The maximal grafting percentage of 135.5% was obtained under the condition of [Ce4+]=5mmol.L-1, [AA]=1mol.L-1, T=60°C and t=3h. Graft copolymerization was suggested to proceed through free radical reaction mechanism. Grafting occurred primarily on chitosan. Acrylic acid was also attempted to be grafted onto Asp. niger cell wall structural polysaccharide, and only 44.2% of grafting percentage was resulted.

  17. Electroactive behavior assessment of poly(acrylic acid)-graphene oxide composite hydrogel in the detection of cadmium

    Bejarano-Jimenez, A.; Escobar-Barrios, V.A.; Kleijn, J.M.; Oritz-Ledon, C.A.; Chazaro-Ruiz, L.F.

    2014-01-01

    Super absorbent polymers of acrylic acid-graphene oxide (PAA-GO) were synthesized with different percentage of chemical neutralization (0, 10, and 20%) of the acrylic acid monomer before its polymerization. The influence of their swelling and adsorption/desorption capacity of cadmium ions in aqueous

  18. SYNTHESIS OF 2—HYDROXYETHYL ACRYLATE BY USING STRONG ACIDIC CATION ION EXCHANGE RESIN AS CATALYST

    GAODabin

    1992-01-01

    2-Hydroxyethyl acrylate is synthesized from acrylic acid and ethylene glycol under a simple and mild condition by using strong acidic cation ion exchange resin as a catalyst,which could be recycled as long as 10 times with high activation.

  19. Poly(acrylic acid) to induce competitive crystallization of a theophylline/oxalic acid cocrystal and a theophylline polymorph

    Jang, Jisun; Kim, Il Won

    2016-01-01

    Polymeric additives to induce competitive crystallization of pharmaceutical compounds were explored. A cocrystal of theophylline and oxalic acid was used as a model system, and poly(acrylic acid), poly(caprolactone), and poly(ethylene glycol) were the additives. The cocrystal formation was selectively hindered with addition of poly(acrylic acid). First the size of the cocrystals were reduced, and eventually the cocrystallization was inhibited to generate neat theophylline crystals. The theophylline crystals were of a distinctively different crystal structure from known polymorphs, based on powder X-ray diffraction. They were also obtained in nanoscale size, when millimeter-scale crystals formed without poly(acrylic acid). Polymeric additives that could form specific interactions with crystallizing compounds seem to be useful tools for the phase and size control of pharmaceutical crystals.

  20. The preparation nad water absorption of a copolymer from konjac-graft-acrylic acid by irradiation

    The konjac and acrylic acid were grafted by 4.0kGy 60Co γ-rays irradiation. The water absorption property of copolymers was studied. The results showed that the optimum feed ratio was konjac powder: acrylic acid: NaOH (9.5mol/L):water=3g: 21ml: 17.8ml: 131ml. And the optimum reation conditions: volume/mass ratio of acrylic acid and konjac was 7:1, neutralization degree of acrylic acid was 55%, gel drying temperature was 30 degree C. The copolymer particle size of 40 ∼ 80 mesh had the largest absorption of water, up to 886.5 times at room temperature. The water-absorption and water-holding capabilities were affected by temperature, and were better at the termperater lower than 60 degree C. The water absorption was also affected by pH and ion concentration of solution, and the ion concentration was the main factor. The largest water absorption at Na2HPO4 - citric acid buffer was only 15.8% of which in distilled water at the optimum pH=6. (authors)

  1. Extraction Equilibrium of Acrylic Acid by Aqueous Two-Phase Systems Using Hydrophilic Ionic Liquids

    As an effective method for extraction of acrylic acid, aqueous two-phase systems based on morpholinium ionic liquids were used in this study. Effects of the alkyl chain length of cation in morpholinium ionic liquids on phase diagram and extraction efficiencies were investigated. Experimental results show that aqueous two phase systems can be formed by adding appropriate amount of morpholinium ionic liquids to aqueous K2HPO4 solutions. It can be found that the ability of morpholinium ionic liquids for phase separation followed the order [HMMor][Br]>[OMMor][Br]>[BMMor][Br]>[EMMor][Br]. There was little difference between binodal curves of imidazolium ionic liquids and those of morpholinium ionic liquids. 50-90% of the extraction efficiency was observed for acrylic acid by aqueous two phase extraction of acrylic acid with morpholinium ionic liquids. It can be concluded that morpholinium ionic liquids/K2HPO4 were effective for aqueous two phases extraction of acrylic acid comparing to imidazolium ionic liquids/K2HPO4 systems because of their lower cost

  2. Depletion of abundant plasma proteins by poly(N-isopropylacrylamide-acrylic acid) hydrogel particles

    Such-Sanmartín, Gerard; Ventura-Espejo, Estela; Jensen, Ole N

    2014-01-01

    the application of pH-sensitive poly(N-isopropylacrylamide-acrylic acid) hydrogel particles for removal of abundant plasma proteins, prior to proteome analysis by MS. Protein depletion occurs by two separate mechanisms: (1) hydrogel particles incubated with low concentrations of plasma capture...

  3. Gold Nanoparticles Protected with Thiol-Derivatized Amphiphilic Poly(epsilon-caprolactone)-b-poly(acrylic acid)

    Javakhishvili, Irakli; Hvilsted, Søren

    2009-01-01

    Amphiphilic poly(epsilon-caprolactone)-b-poly(acrylic acid) (HS-PCL-b-PAA) with a thiol functionality in the PCL terminal has been prepared in a novel synthetic cascade. Initially, living anionic ring-opening polymerization (ROP) of epsilon-caprolactone (epsilon-CL) employing the difunctional...

  4. Selective oxidation of propane to acrylic acid over mixed metal oxide catalysts

    Wei Zheng; Zhenxing Yu; Ping Zhang; Yuhang Zhang; Hongying Fu; Xiaoli Zhang; Qiquan Sun; Xinguo Hu

    2008-01-01

    The effects of metal atomic ratio, water content, oxygen content, and calcination temperature on the catalytic perfor-mances of MoVTeNbO mixed oxide catalyst system for the selective oxidation of propane to acrylic acid have been investigated and discussed. Among the catalysts studied, it was found that the MoVTeNbO catalyst calcined at a temperature of 600 ℃ showed the best performance in terms of propane conversion and selectivity for acrylic acid under an atmosphere of nitrogen. An effective MoVTeNbO oxide catalyst for propane selective oxidation to acrylic acid was obtained with a combination of a preferred metal atomic ratio (Mo1 V0.31Te0.23Nb0.12). The optimum reaction condition for the selective oxidation of propane was the molar ratio of C3H81 :O2 : H2O : N1 = 4.4 : 12.8 : 15.3 : 36.9. Under such conditions, the conversion of propane and the maximum yield of acrylic acid reached about 50% and 21%, respectively.

  5. Monitor of Polymerization of Inverse Microemulsions Containing Methyl Methacrylate and Acrylic Acid

    Xiao LI; Sheng Ping XIA; Wei Jie ZENG; Wei Ying ZHANG; Sheng Xiong DONG

    2006-01-01

    The polymerization of the inverse microemulsions composed of methyl methacrylate,acrylic acid, sodium dodecyl sulfate and water was monitored by refractometer, conductometer and time-resolved light scattering device. The results showed that refractive index, conductivity or intensity distribution of scattered light changed along with polymerization, and different processes of polymerization could be identified.

  6. Cisplatin-incorporated nanoparticles of poly(acrylic acid-co-methyl methacrylate copolymer

    Lee KD

    2013-08-01

    Full Text Available Kyung Dong Lee,1,* Young-Il Jeong,2,* Da Hye Kim,3,4 Gyun-Taek Lim,2 Ki-Choon Choi5 1Department of Oriental Medicine Materials, Dongshin University, Naju, South Korea; 2Department of Polymer Engineering, Chonnam National University, Gwangju, South Korea; 3Faculty of Life and Environmental Science, Shimane University, Matsue, Japan; 4United Graduate School of Agricultural Sciences, Tottori University, Tottori, Japan; 5Grassland and Forages Division, National Institute of Animal Science, Rural Development Administration, Cheonan, South Korea *These authors contributed equally to this work Background: Although cisplatin is extensively used in the clinical field, its intrinsic toxicity limits its clinical use. We investigated nanoparticle formations of poly(acrylic acid-co-methyl methacrylate (PAA-MMA incorporating cisplatin and their antitumor activity in vitro and in vivo. Methods: Cisplatin-incorporated nanoparticles were prepared through the ion-complex formation between acrylic acid and cisplatin. The anticancer activity of cisplatin-incorporated nanoparticles was assessed with CT26 colorectal carcinoma cells. Results: Cisplatin-incorporated nanoparticles have small particle sizes of less than 200 nm with spherical shapes. Drug content was increased according to the increase of the feeding amount of cisplatin and acrylic acid content in the copolymer. The higher acrylic acid content in the copolymer induced increase of particle size and decrease of zeta potential. Cisplatin-incorporated nanoparticles showed a similar growth-inhibitory effect against CT26 tumor cells in vitro. However, cisplatin-incorporated nanoparticles showed improved antitumor activity against an animal tumor xenograft model. Conclusion: We suggest that PAA-MMA nanoparticles incorporating cisplatin are promising carriers for an antitumor drug-delivery system. Keywords: cisplatin, nanoparticle, poly(acrylic acid-co-methyl methacrylate, ion complexes

  7. Adsorption of uranium ions by crosslinked polyester resin functionalized with acrylic acid from aqueous solutions

    In this paper, the crosslinked polyester resin containing acrylic acid functional groups was used for the adsorption of uranium ions from aqueous solutions. For this purpose, the crosslinked polyester resin of unsaturated polyester in styrene monomer (Polipol 353, Poliya) and acrylic acid as weight percentage at 80 and 20%, respectively was synthesized by using methyl ethyl ketone peroxide (MEKp, Butanox M60, Azo Nobel)-cobalt octoate initiator system. The adsorption of uranium ions on the sample (0.05 g copolymer and 5 mL of U(VI) solution were mixed) of the crosslinked polyester resin functionalized with acrylic acid was carried out in a batch reactor. The effects of adsorption parameters of the contact time, temperature, pH of solution and initial uranium(VI) concentration for U(VI) adsorption on the crosslinked polyester resin functionalized with acrylic acid were investigated. The adsorption data obtained from experimental results depending on the initial U(VI) concentration were analyzed by the Freundlich, Langmuir and Dubinin-Radushkevich (D-R) adsorption isotherms. The adsorption capacity and free energy change were determined by using D-R isotherm. The obtained experimental adsorption data depending on temperature were evaluated to calculate the thermodynamic parameters of enthalpy (ΔHo), entropy (ΔSo) and free energy change (ΔGo) for the U(VI) adsorption on the crosslinked polyester resin functionalized with acrylic acid from aqueous solutions. The obtained adsorption data depending on contact time were analyzed by using adsorption models such as the modified Freundlich, Elovich, pseudo-first order and pseudo-second-order kinetic models. (author)

  8. Grafting of acrylic acid onto polytetrafluoroethylene (PTFE) micropowder via pre-irradiation

    Grafting of acrylic acid (AAc) onto the surface of PTFE micropowder was performed by pre-irradiation method, in order to improve their dispersion in aqueous solution.The effects of various experimental parameters on the degree of grafting(G) were separately investigated, including: volume fraction of AAc, proper addition of concentrated sulfuric acid, mass fraction of inhibitor and reaction time. The result shows that G is increasing with increment of AAc concentration below 50%, and can be enhanced by adding a proper amount of sulfuric acid. Under our experimental conditions, G reached its saturated value when the mass concentration of the inhibitor was 0.8 g/L and the reaction time was 3 h. The introduction of more than 10% of poly(acrylic acid) chain on PTFE micropowder results in the good dispersion of PTFE micropowder in aqueous NaOH solution. (authors)

  9. CHARACTERIZATION OF RADIATION GRAFTING DEGREE OF POLYSTYRENE g-ACRYLIC ACID BY XPS

    CHE Jitai; ZHANG Wanxi

    1990-01-01

    It this work, characterization of radiation grafting degree of polystyrene-g-acrylic acid by XPS was studied. It is found that along with the main peak C1s there is a photoelectron peak at 289.0 eV that appears to be C1s of -C(=O)-OH group and shows the presence ofpolyacrylic acid grafted on the polystyrene.The grafting degree obtained by XPS is in agreement with that from the gravimetric method.

  10. Oxidative dehydration of glycerol to acrylic acid over vanadium-impregnated zeolite beta

    Pestana, Carolina F.M.; Guerra, Antonio C.O.; Turci, Cassia C. [Universidade Federal do Rio de Janeiro, RJ (Brazil). Inst. de Quimica; Ferreira, Glaucio B. [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Inst. de Quimica; Mota, Claudio J.A., E-mail: cmota@iq.ufrj.br [INCT Energia e Ambiente, Universidade Federal do Rio de Janeiro, RJ (Brazil)

    2013-01-15

    The oxidative dehydration of glycerol to acrylic acid was studied over vanadium-impregnated zeolite Beta. Catalysts were prepared by wet impregnation of ammonium metavanadate over ammonium-exchanged zeolite Beta, followed by air calcination at 823 K. Impregnation reduced the specific surface area, but did not significantly affected the acidity (Bronsted and Lewis) of the zeolites. The catalytic evaluation was carried out in a fixed bed flow reactor using air as the carrier and injecting glycerol by means of a syringe pump. Acrolein was the main product, with acetaldehyde and hydroxy-acetone (acetol) being also formed. Acrylic acid was formed with approximately 25% selectivity at 548 K over the impregnated zeolites. The result can be explained by XPS (X-ray photoelectron spectroscopy) measurements, which indicated a good dispersion of the vanadium inside the pores. (author)

  11. Properties of radiation curable hyperbranched polyurethane acrylate from palm oil oleic acid

    Radiation curable hyperbranched urethane acrylate (HBPUA) from oleic acid of palm oil was synthesized aided by p-toluene sulfonic acid as a catalyst. This mixture was then used as the core (HBP-1) and reacted with palm oil oleic acid to form the hyperbranched polyol (HBP-2). HBPUA was prepared by reacting HBP-2 resin with diisocyanate and hydroxyl-containing acrylate monomer with the presence of 0.1-2 wt% dibutyltin dilaurate as a catalyst. The reaction was confirmed by several analytical data i.e. hydroxyl value (OHV), Fourier Transform infrared (FT IR) spectroscopy gel permeation chromatography (GPC) and nuclear magnetic resonance (NMR) spectroscopy analyses. The HBPUA was easily curable when subjected to electron beam (EB) or ultraviolet (UV) radiation. (authors)

  12. Oxidative dehydration of glycerol to acrylic acid over vanadium-impregnated zeolite beta

    The oxidative dehydration of glycerol to acrylic acid was studied over vanadium-impregnated zeolite Beta. Catalysts were prepared by wet impregnation of ammonium metavanadate over ammonium-exchanged zeolite Beta, followed by air calcination at 823 K. Impregnation reduced the specific surface area, but did not significantly affected the acidity (Bronsted and Lewis) of the zeolites. The catalytic evaluation was carried out in a fixed bed flow reactor using air as the carrier and injecting glycerol by means of a syringe pump. Acrolein was the main product, with acetaldehyde and hydroxy-acetone (acetol) being also formed. Acrylic acid was formed with approximately 25% selectivity at 548 K over the impregnated zeolites. The result can be explained by XPS (X-ray photoelectron spectroscopy) measurements, which indicated a good dispersion of the vanadium inside the pores. (author)

  13. Superabsorbent biphasic system based on poly(lactic acid) and poly(acrylic acid)

    Sartore, Luciana; Pandini, Stefano; Baldi, Francesco; Bignotti, Fabio

    2016-05-01

    In this research work, biocomposites based on crosslinked particles of poly(acrylic acid), commonly used as superabsorbent polymer (SAP), and poly-L-lactic acid (PLLA) were developed to elucidate the role of the filler (i.e., polymeric crosslinked particles) on the overall physico-mechanical behavior and to obtain superabsorbent thermoplastic products. Samples prepared by melt-blending of components in different ratios showed a biphasic system with a regular distribution of particles, with diameter ranging from 5 to 10 μm, within the PLLA polymeric matrix. The polymeric biphasic system, coded PLASA i.e. superabsorbent poly(lactic acid), showed excellent swelling properties, demonstrating that cross-linked particles retain their superabsorbent ability, as in their free counterparts, even if distributed in a thermoplastic polymeric matrix. The thermal characteristics of the biocomposites evidence enhanced thermal stability in comparison with neat PLLA and also mechanical properties are markedly modified by addition of crosslinked particles which induce regular stiffening effect. Furthermore, in aqueous environments the particles swell and are leached from PLLA matrix generating very high porosity. These new open-pore PLLA foams, produced in absence of organic solvents and chemical foaming agents, with good physico-mechanical properties appear very promising for several applications, for instance in tissue engineering for scaffold production.

  14. Determination of acrylamide and acrylic acid by isocratic liquid chromatography with pulsed electrochemical detection.

    Casella, Innocenzo G; Pierri, Marianna; Contursi, Michela

    2006-02-24

    The electrochemical behaviour of the polycrystalline platinum electrode towards the oxidation/reduction of short-chain unsaturated aliphatic molecules such as acrylamide and acrylic acid was investigated in acidic solutions. Analytes were separated by reverse phase liquid chromatographic and quantified using a pulsed amperometric detection. A new two-step waveform, is introduced for detection of acrylamide and acrylic acid. Detection limits (LOD) of 20 nM (1. 4 microg/kg) and 45 nM (3.2 microg/kg) were determined in water solutions containing acrylamide and acrylic acid, respectively. Compared to the classical three-step waveform, the proposed two-step waveform shows favourable analytical performance in terms of LOD, linear range, precision and improved long-term reproducibility. The proposed analytical method combined with clean-up procedure accomplished by Carrez clearing reagent and subsequent extraction with a strong cation exchanger cartridges (SPE), was successfully used for the quantification of low concentrations of acrylamide in foodstuffs such as coffee and potato fries. PMID:16426623

  15. Nanoparticles of Block Ionomer Complexes from Double Hydrophilic Poly(acrylic acid-b-poly(ethylene oxide-b-poly(acrylic acid Triblock Copolymer and Oppositely Charged Surfactant

    Sun Yuelong

    2009-01-01

    Full Text Available Abstract The novel water-dispersible nanoparticles from the double hydrophilic poly(acrylic acid-b-poly(ethylene oxide-b-poly(acrylic acid (PAA-b-PEO-b-PAA triblock copolymer and oppositely charged surfactant dodecyltrimethyl ammonium bromide (DTAB were prepared by mixing the individual aqueous solutions. The structure of the nanoparticles was investigated as a function of the degree of neutralization (DN by turbidimetry, dynamic light scattering (DSL,ζ-potential measurement, and atomic force microscope (AFM. The neutralization of the anionic PAA blocks with cationic DTAB accompanied with the hydrophobic interaction of alkyl tails of DTAB led to formation of core–shell nanoparticles with the core of the DTAB neutralized PAA blocks and the shell of the looped PEO blocks. The water-dispersible nanoparticles with negative ζ-potential were obtained over the DN range from 0.4 to 2.0 and their sizes depended on the DN. The looped PEO blocks hindered the further neutralization of the PAA blocks with cationic DTAB, resulting in existence of some negative charged PAA-b-PEO-b-PAA backbones even when DN > 1.0. The spherical and ellipsoidal nature of these nanoparticles was observed with AFM.

  16. Preparation of poly (acrylic acid)-modified chitosan amphiphilic gels by γ-rays irradiation

    Poly (acrylic acid)-modified chitosan amphiphilic gels were prepared via O-maleoyl-N-phthaloyl- chitosan as an intermediate by grafting with poly (acrylic acid). The reaction was carried out in a homogeneous sys- tem by γ-ray irradiation. Evidence of grafting was obtained from FTIR spectroscopy. The effects for grafting reaction were investigated systematically. Results show that the grafting degree depends on monomer concentration and ab- sorbed dose. The swelling behavior of chitosan samples with different grafting degree was studied in different buffers as a function of pH. It can be found that all the samples swollen slightly at low pH but very well at high pH. More- over, the swelling behavior of chitosan samples in DMF has been evaluated. (authors)

  17. Super absorbent Prepared by Radiation Induced Graft Copolymerization of Acrylic Acid onto Cassava Starch

    Full text: Super absorbent was synthesized by radiation-induced graft polymerization of acrylic acid onto cassava starch. Parameters such as the absorbed dose and the amount of monomer were investigated in order to determine the optimum conditions for the grafting polymerization. Water retention, germination percentage and germination energy were determined in order to evaluate the possibility of super absorbent in agricultural applications, especially in arid regions. The graft copolymer was characterized by FTIR. Results indicated that the sand mixed with 0.1%wt super absorbent can absorb more water than the sand without super absorbent. The germination energy of corn seeds mixed with 0.5% super absorbent was obviously higher than those without super absorbent. These experimental results showed that the super absorbent has considerable effect on seed germination and the growth of young plants. Keywords: Super absorbent, Radiation, Acrylic acid, Cassava starch

  18. Preparation of poly(acrylic acid) particles by dispersion polymerization in an ionic liquid.

    Minami, Hideto; Kimura, Akira; Kinoshita, Keigo; Okubo, Masayoshi

    2010-05-01

    Poly(acrylic acid) (PAA) particles were successfully prepared by dispersion polymerization of acrylic acid in ionic liquid, N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium bis(trifluoro-methanesulfonyl)amide ([DEME][TFSA]) at 70 degrees C with low hydrolysis grade (35.4%) poly(vinyl alcohol) as stabilizer. Interestingly, the PAA particles were easily extracted as particle state with water. Thus, the PAA particles had a cross-linked structure during the polymerization without cross-linker. Moreover, it was also noted that the cross-linking density of the PAA particles could be controlled by thermal treatment at various temperatures in [DEME][TFSA] utilizing the advantages of nonvolatility and high thermal stability of the ionic liquid. PMID:20043688

  19. Removal of Dyes from Aqueous Solutions Using Radiation Synthesized (2-Hydroxyethyl Methacrylate/Acrylic acid) Hydrogels

    Acrylic acid/2-hydroxyethyl methacrylate super absorbent hydrogels (AAc/ HEMA) were prepared by γ-radiation copolymerization of 2-hydroxyethyl methacrylate (HEMA) and acrylic acid (AAc). Characterization of AAc/HEMA hydrogel was done by FTIR, TGA, SEM and XRD. The swelling properties were studied as a function of time, ph and irradiation dose. The diffusion behavior of water into these hydrogels followed the Fickian character at all investigated irradiation doses. The adsorption of Direct Congo Red and Direct Blue dyes onto the AAc/ HEMA hydrogel was studied. Physico-chemical parameters like dye concentration, solution ph and temperature were varied to characterize the adsorption phenomenon. Experimental data were modeled by Freundlich isotherm. Thermodynamic parameters ( ΔHo, ΔGo and ΔSo ) were evaluated for the dyes adsorbent systems, which suggest that the adsorption process is a typical physical process and endothermic in nature

  20. Pre-irradiation induced emulsion co-graft polymerization of acrylonitrile and acrylic acid onto a polyethylene nonwoven fabric

    A pre-irradiation induced emulsion co-graft polymerization method was used to introduce acrylonitrile and acrylic acid onto a PE nonwoven fabric. The use of acrylic acid is meant to improve the hydrophilicity of the modified fabric. The kinetics of co-graft polymerization were studied. The existence of polyacrylonitrile (PAN) and poly(acrylic acid) (PAAc) graft chains was proven by Fourier transform infrared spectroscopy (FTIR) analysis. The existence of the nitrile groups in the graft chains indicates that they are ready for further amidoximation and adsorption of heavy metal ions. - Highlights: • Acrylonitrile and acrylic acid were co-grafted onto a PE nonwoven fabric. • Pre-irradiation induced emulsion graft polymerization technique is applied. • The existence of AAc resulted in the increased hydrophilicity of the grafted fabric

  1. Preparation and evaluation of chitosan-poly (acrylic acid hydrogels as stomach specific delivery for amoxicillin and metronidazole

    Hemant Yadav K

    2007-01-01

    Full Text Available The objective of the present work was to develop stomach specific delivery systems for amoxicillin and metronidazole using chitosan and poly(acrylic acid hydrogels. Chitosan and poly(acrylic acid hydrogels were prepared with different composition of copolymers. The hydrogels were evaluated for swelling studies, mucoadhesive studies, in vitro drug release, scanning electron microscopic and FTIR analysis. The effect of chitosan and poly (acrylic acid on swelling and in vitro drug release was carried out. The n value calculated was < 0.5 for all the formulations containing amoxicillin and metronidazole indicating Fickian diffusion mechanism. The hydrogels with chitosan and poly (acrylic acid ratio of 0.25:1 showed greater mucoadhesive property, maximum swelling and complete release of drugs, hence can be used for stomach specific delivery of drugs.

  2. Flocculation Efficiency of Poly(Acrylamide-Co-Acrylic Acid) Obtained by Electron Beam Irradiation

    Gabriela Craciun; Elena Manaila; Maria-Daniela Stelescu

    2013-01-01

    A correlation between physicochemical characteristics of flocculants obtained by electron beam irradiation and their efficiency for wastewater treatment is presented. For real wastewater treatment, our interest was focused upon total suspended solids, fatty matter, and chemical oxygen demand. Flocculation studies were carried out using a standard jar test. A treatment option based on poly(acrylamide-co-acrylic acid) for wastewater taken from a slaughterhouse plant is presented.

  3. Modification of hydrophobic polypeptide-based film by blending with hydrophilic poly(acrylic acid)

    Guoquan Zhu; Fagang Wang; Qiaochun Gao; Yuying Liu

    2013-01-01

    In this study, a series of poly(γ-benzyl L-glutamate)/poly(acrylic acid) (PBLG/PAA) polymer blend films were prepared by casting the polymer blend solution in dimethylsulfoxide (DMSO). The structure and morphology of the polymer blend film were investigated by Fourier Transform Infrared Spectroscopy (FT-IR) and Scanning Electron Microscopy (SEM). Thermal, mechanical, and chemical properties of PBLG/PAA polymer blend films were studied by Differential Scanning Calorimetry (DSC), Thermogra...

  4. Investigation on the Inverse Emulsion Polymerization of Acrylic Acid

    2002-01-01

    Polyacrylic acid particles in nano-scale were synthesized using an inverse (W/O) emulsion polymerization method. The particle size and size change of inverse micelles which solubilize a part of monomer solution was monitored by PCS (photon correlation spectroscopy) and the particles of polyacrylic acid were viewed in scanning electron microscope for the first time. It was concluded that the inverse micelles were primarily the polymerization reaction sites.

  5. Synthesis and characterization of kappaphycus seaweed-poly (acrylic) acid superabsorbent hydrogel for agricultural use

    The main objective of this research is to synthesize and characterize kappaphycus seaweed-poly (acrylic) acid superabsorbent hydrogel for agricultural use. The superabsorbent polymers (SAPs), KCSW: PAA hydrogels were synthesized by using gamma radiation technique from Cobalt-60 source at absorbed dose 0f 5, 10 and 15 kGy. The effect of absorbed dose, seaweed concentration, and concentration of acrylic acid on the degree of swelling was studied and optimum swelling conditions were established. Irradiated samples of 3% KCSW, 50% neutralized AAC at an absorbed dose of 10kGy gave the highest degree of swelling and gel fraction and were found to be suitable for application in the agriculture. Samples with different concentrations of acrylic acid were characterized using FTIR and TGA. The water retention experiment in sandy soil showed high water retention capacity of KCSW: PAA hydrogel at a value of 92% for a period of 7 days. Effect of the germination of mung bean showed very promising result of 78% germination.(author)

  6. Swelling of Bacterial Cellulose-Acrylic Acid Hydrogels: Sensitivity Towards External Stimuli

    This study evaluated various environmental factors affecting the swelling degree of bacterial cellulose-acrylic acid hydrogels. Aqueous bacterial cellulose-acrylic acid (4:1) mixtures were prepared and subjected to electron beam irradiation at 30 and 50 kGy. Swelling rate under influenced of pH, temperature and ionic strength was investigated from 1 to 24 hours. Swelling degree of hydrogels was dependent on irradiation dose: those synthesized at 50 kGy exhibited significant higher swelling degree (p<0.0001) in methanol (619 %) compared to water (510 %) at room temperature after 24 hours. External ionic strength affected swelling, for example elevation in sodium chloride concentration decreased swelling degree. Hydrogels were also sensitive to pH: swelling increased with increasing pH and was optimal at pH 7. Swelling also increased with increasing temperature from 25 to 50 degree Celsius. In conclusion, the ability of electron irradiated bacterial cellulose-acrylic acid hydrogels to respond to various external environment make it a material to be developed as an active delivery system for drugs, proteins and hormones. (author)

  7. Influence of ozone and paracetic acid disinfection on adhesion of resilient liners to acrylic resin

    2016-01-01

    PURPOSE The aim of this study was to evaluate the effect of paracetic acid (PAA) and ozone disinfection on the tensile bond strength (TBS) of silicone-based resilient liners to acrylic resins. MATERIALS AND METHODS One hundred and twenty dumbbell shaped heat-polymerized acrylic resins were prepared. From the mid segment of the specimens, 3 mm of acrylic were grinded off and separated parts were reattached by resilient liners. The specimens were divided into 2 control (control1, control7) and 4 test groups of PAA and ozone disinfection (PAA1, PAA7, ozone1 and ozone7; n=10). While control groups were immersed in distilled water for 10 min (control1) and 7 days (control7), test groups were subjected to PAA (16 g/L) or ozone rich water (4 mg/L) for 1 cycle (10 min for PAA and 60 min for ozone) per day for 7 days prior to tensile tests. Measurements of the TBS were analyzed using 3-way ANOVA and Tukey's HSD test. RESULTS Adhesive strength of Mollosil decreased significantly by application of ozone disinfection. PAA disinfection had no negative effect on the TBS values of Mollosil and Molloplast B to acrylic resin. Single application of ozone disinfection did not have any negative effect on TBS values of Molloplast B, but prolonged exposure to ozone decreased its adhesive strength. CONCLUSION The adhesion of resilient liners to acrylic was not adversely affected by PAA disinfection. Immersion in ozonated water significantly decreased TBS of Mollosil. Prolonged exposure to ozone negatively affects adhesion of Molloplast B to denture base materials. PMID:27555898

  8. Impact of Acrylic Acid on ASP Flooding Performance: Interfacial Tension Behaviour

    Shuaib Ahmed Kalwar

    2014-01-01

    Full Text Available In chemical EOR, interfacial tension plays one of the important roles in carbonate reservoirs. Carbonate reservoirs are composed of calcium and magnesium minerals which affect the performance of alkali and surfactants to reduce interfacial tension. In this study, acrylic acid was used to inhibit precipitation and to create a compatible solution without any precipitations. The impact of acrylic acid on interfacial tension was investigated using various inhibitor concentrations with a hard brine composition of 59, 940 TDS. Sodium metaborate, alpha olefin sulfonate and internal olefin sulfonate were screened as promising chemicals for interfacial tension. Various fluid-fluid compatibility tests were first performed to find the optimum acid-alkali ratio to prevent any precipitations. The optimum acid-alkali ratio was found to be 0.6:1.0. This ratio was then used to keep all solution without any precipitations for 30 days at 80°C. It was also observed that the increase in acid-alkali concentrations can significantly reduce the interfacial tension. Using the optimum concentration for acid, alkali and surfactant, the interfacial tension reduced from 14.9-0.401 mN m-1.

  9. The active component of vanadium-molybdenum catalysts for the oxidation of acrolein to acrylic acid

    The catalytic properties of the vanadium-molybdenum oxide system were investigated in the oxidation of acrolein to acrylic acid. The active component of the catalyst is the compound VMo3O11, the maximum amount of which is observed at a content of 7-15 mole% V2O4. The compound VMo3O11 is formed in the thermodecomposition of silicomolybdovanadium heteropoly acids or isopoly compounds, reduced with respect to vanadium, and contains V4+ and Mo6+. The optimum treatment for the formation of this compound is treatment in the reaction mixture at 400 degrees C

  10. ESTERIFICATION OF ACRYLIC ACID WITH 1-BUTANOL IN LIQUID PHASE CATALYZED WITH AL-MCM-41

    Edson Avellaneda Maytán; Gustavo Paim Valença

    2010-01-01

    This work studies the esterification of acrylic acid with 1-butanol using Al-MCM-41 as catalyst with different degrees of acidity at different temperatures. Al-MCM-41 synthesis was made from bromate Cetyl trimethyl ammonium using as router agent, NH4OH (25%), deionized H2O and Al2(SO4)3. Catalytic tests were carried out by groups and worked with temperature ranges among (333 to 348) K and a small sample was collected at predetermined intervals of time for subsequent gas chromatography analysi...

  11. Ultra-Thin Films of Poly(acrylic acid)/Silver Nanocomposite Coatings for Antimicrobial Applications

    Alaa Fahmy; Eisa, Wael H.; Mohamed Yosef; Ali Hassan

    2016-01-01

    In this work not only colloids of poly(acrylic acid) (PAA) embedded with silver nanoparticles (Ag-NPs) but thin films (10 nm) also were deposited using electrospray deposition technique (ESD). A mixture of sodium borohydride (NaBH4) and ascorbic acid (AA) were utilized to reduce the silver ions to generate Ag-NPs in the PAA matrix. Moreover, sodium tricitrate was used to stabilize the prepared colloids. The obtained colloids and films were characterized using UV-visible, transmission electron...

  12. Structure and Proton Conductivity in Mixtures of Poly(acrylic acid) and Imidazole

    Yang, Han-Chang; Griffin, Philip J.; Winey, Karen I.; University of Pennsylvania Team

    2015-03-01

    Proton conductivity in polymer electrolyte membranes (PEMs) typically involves water, which requires that during operation the humidity of the PEM be carefully controlled. In contrast, anhydrous protic polymer membranes promote proton transport by incorporating heterocyclic molecules, such as imidazole and its derivatives, into acid-containing polymers. In this work, we explore the interplay between nanoscale-structure and proton conduction of poly(acrylic acid) (PAA) blended at varying compositions with 2-ethyl-4-methylimidazole (EMI). We present the glass transition temperature from differential scanning calorimetry, morphology characterization from X-ray scattering, and proton conductivity from electrical impedance spectroscopy.

  13. Bioinspired bioadhesive polymers: dopa-modified poly(acrylic acid) derivatives.

    Laulicht, Bryan; Mancini, Alexis; Geman, Nathanael; Cho, Daniel; Estrellas, Kenneth; Furtado, Stacia; Hopson, Russell; Tripathi, Anubhav; Mathiowitz, Edith

    2012-11-01

    The one-step synthesis and characterization of novel bioinspired bioadhesive polymers that contain Dopa, implicated in the extremely adhesive byssal fibers of certain gastropods, is reported. The novel polymers consist of combinations of either of two polyanhydride backbones and one of three amino acids, phenylalanine, tyrosine, or Dopa, grafted as side chains. Dopa-grafted hydrophobic backbone polymers exhibit as much as 2.5 × the fracture strength and 2.8 × the tensile work of bioadhesion of a commercially available poly(acrylic acid) derivative as tested on live, excised, rat intestinal tissue. PMID:23008096

  14. Antibacterial activity of chitosan and the interpolyelectrolyte complexes of poly(acrylic acid-chitosan

    Hortensia Ortega-Ortiz

    2010-06-01

    Full Text Available The antimicrobial activity of chitosan and water soluble interpolyelectrolyte complexes of poly(acrylic acid-chitosan was studied. Chitosans of two different molecular weights were tested at different concentration for 0.5 to 5 g·L-1 as antimicrobial agents against P. aeruginosa and P. oleovorans. In both cases, the best microbial inhibition was obtained with the concentration of 5 g·L-1. However, the interpolyelectrolyte complexes of poly(acrylic acid-chitosan with composition φ =2 produced higher antibacterial activity than the two chitosans at the concentration of 0.5 g·L-1. The NPEC2 complex was more effective than chitosans. This could be attributed to the number of moles of the amino groups of chitosan and the carboxylic acid groups of the interpolyelectrolyte complexes poly(acrylic acid.A atividade antimicrobiana de quitosana e complexos interpolieletrolíticos hidrossoluvéis de poli(ácido acrílico-quitosana foi estudada. Quitosanas de dois diferentes pesos moleculares foram testados em diferentes concentrações, 0,5 a 5 g • L-1, como agentes antimicrobianos nas P. aeruginosa e P. oleovorans. Em ambos os casos, obteu-se a melhor inibição microbiana com a concentração de 5 g • L-1, no entanto os complexos interpolieletrolíticos de poli (ácido acrílico-quitosana com composição φ = 2 apresentaram maior atividade antibacteriana do que os dois quitosans na concentração de 0,5 g • L-1. O complexo NPEC2 foi mais eficaz do que as quitosanas, sendo que o resultado pode ser atribuído ao número de moles dos grupos aminos da quitosana e aos grupos carboxílicos dos complexos de poli(ácido acrílico.

  15. Partial oxidation of D-xylose to maleic anhydride and acrylic acid over vanadyl pyrophosphate

    Xylose is the second most abundant sugar after glucose. Despite its tremendous potential to serve as a renewable feedstock, few commercial processes exploit this resource. Here, we report a new technology in which a two-fluid nozzle atomizes a xylose-water solution into a capillary fluidized bed operating above 300 °C. Xylose-water droplets form at the tip of the injector, vaporize then react with a heterogeneous mixed oxide catalyst. A syringe pump metered the solution to the reactor charged with 1 g of catalyst. Product yield over vanadyl pyrophosphate was higher compared to molybdenum trioxide-cobalt oxide and iron molybdate; it reached 25% for maleic anhydride, 17% for acrylic acid and 11% for acrolein. Gas residence time was 0.2 s. The catalyst was free of coke even after operating for 4 h – based on a thermogravimetric analysis of catalyst withdrawn from the reactor. Below 300 °C, powder agglomerated at the tip of the injector at 300 °C; it also agglomerated with a xylose mass fraction of 7% in water. - Highlights: • D-xylose reacts to form maleic anhydride and acrylic acid above 250 °C. • Vanadyl pyrophosphate is both active and selective for maleic and acrylic acid. • Acid and acrolein yield approaches 50% for a xylose mass fraction of 3% in water. • Catalyst agglomerates at low temperatures and high xylose aqueous mass fraction. • Atomization quality is a determining factor to minimize agglomeration

  16. Synthesis of superabsorbent hydrogel by radiation crosslinking of acrylic acid, semi-refined kappa-carrageenan and sugarcane bagasse blend

    Superabsorbent hydrogels have three-dimensional networks that enable it to exhibit great water absorption capacity leading to its promising applications. However, existing commercial hydrogels are mainly acrylic acid which causes environmental problems. In this study, the incorporation of agricultural waste as filler and polysaccharide from natural sources as binder for the production of superabsorbent hydrogel was done to reduce the use of acrylic acid as well as its environmental impact while adding value to the incorporated materials. A series of superabsorbent hydrogel with the blend of acrylic acid, semi-refined kappa carrageenan and sugarcane bagasse were synthesized by radiation crosslinking. The gel fraction and swelling capacity of the hydrogels were determined and studied. The characterizations were facilitated by Fourier transform infrared spectroscopy technique (FTIR) and Thermogravimetric Analysis (TGA). In the results obtained from analyses, the characteristic peaks of acrylic acid and sugarcane bagasse were observed in the FTIR spectra and the three step peaks if synthesized hydrogel in its TGA implies an improvement in thermal stability of the product. The synthesized superabsorbent hydrogel blends had exhibited comparable gel fraction to that of the polyacrylic acid hydrogel, had great swelling capacity, and achieved equilibrium degree of swelling within 72-96 hours. The optimum synthesized superabsorbent hydrogel is 3% semi-refined kappa-carrageenan, 3% sugarcane bagasse, 15% acrylic acid neutralize up to 50% and irradiated at 15kGy dose which exhibited a swelling of 599.53 and gel fraction of 39.73. (author)

  17. Use of acrylic acid in the synthesis of molecularly imprinted polymers for the analysis of cyproheptadine

    The synthesis and comparative characterization of molecularly imprinted polymers (MIPs) with cyproheptadine (CYP), using two different monomers, acrylic acid (AA) and methacrylic acid (MAA), are described. Polyacids (PA) [poly(methacrylic acid) (PMAA) and poly(acrylic acid) (PAA)] were obtained by the radical polymerization of MAA and AA, respectively, in dichloromethane as the porogen solvent-imprinted medium. The non-covalent imprinting process was performed via thermal decomposition of an azo-initiator at 60 deg. C, using ethylene glycol dimethacrylate as the cross-linker and 2,2'-azobis(2-methylpropionitrile) as the initiator. The selectivities of MIPs and NIPs particles were evaluated in binding experiments of the four synthesized polymeric materials (MIPaa, MIPmaa, NIPmaa and NIPaa) with CYP. The effects of monomers on: a) the surface morphology, b) the binding capacity and c) the swelling properties of imprinted and non-imprinted polymers were studied and are presented here. Polymer material morphology was assessed with scanning electron microscopy (SEM). This revealed differences in monomer function, depending on which one was employed, as well as differences in function when polymerization occurred in the presence of template or without it. Non-specific retention of the template to NIPs was higher for NIPs-PAA polymers than for NIPs-PMAA materials. In terms of specific binding (ΔQ = QMIP - QNIP), MIPmaa showed the greatest value (53.47%) in comparison with MIPaa (50.07%)

  18. Synthesis of acrylic prepolymer

    An acrylic prepolymer was synthesized from glycidyl methacrylate (GMA), butyl methacrylate (BMA), methyl methacrylate (MMA) and acrylic acid (AA). Butyl acetate (BAc), benzoyl peroxide (BzO), 4-methoxyphenol (MPh) and triethylamine (TEA) were used as solvent, initiator, inhibitor and catalyst respectively. Observations of the synthesis leading to the formation of acrylic prepolymer are described. (author)

  19. Physicochemical and electrochemical characterization of battery separator prepared by radiation induced grafting of acrylic acid onto microporous polypropylene membranes

    2009-05-01

    Full Text Available Mutual radiation grafting technique was used to graft acrylic acid on micrometer thick micro-porous polypropylene membrane using high-energy gamma radiation. Grafting could not be achieved in aqueous acrylic acid solution. The presence of Mohr’s salt effectively retarded the homopolymerization of acrylic acid but did not lead to grafting enhancement. Mohr’s salt in presence of acids was found to be effective in enhancing the grafting yield. Contact angle measurement studies of the grafted and radiation treated polypropylene showed that initial grafting as well as radiation treatment of poly(propylene in aqueous medium and in presence of Mohr’s salt enhances its affinity towards the grafting solution. The enhancement in the polar component of surface energy of treated polypropylene membrane is the primary cause of grafting enhancement. The membranes grafted to an extent of ~20% were found to perform comparably with the battery separator presently being used by battery industry.

  20. Synthesis of hemicellulose-acrylic acid graft copolymer super water absorbent resin by ultrasonic irradiation technology

    Liu, Fangfang; Conghui DU; Linya ZHANG

    2015-01-01

    The hemicellulose super water absorbent resin is prepared by using ultrasonic irradiation technology, with the waste liquid produced during the preparation of viscose fiber which contains a large amount of hemicellulose as raw material, acrylic acid as graft monomer, N,N’-methylene bis acrylamide (NMBA) as cross linking agent, and (NH4)2S2O8-NaHSO3 as the redox initiation system. The synthesis conditions, structure and water absorption ability of resin are discussed. The results indicate that...

  1. Modification of hydrophobic polypeptide-based film by blending with hydrophilic poly(acrylic acid

    Guoquan Zhu

    2013-01-01

    Full Text Available In this study, a series of poly(γ-benzyl L-glutamate/poly(acrylic acid (PBLG/PAA polymer blend films were prepared by casting the polymer blend solution in dimethylsulfoxide (DMSO. The structure and morphology of the polymer blend film were investigated by Fourier Transform Infrared Spectroscopy (FT-IR and Scanning Electron Microscopy (SEM. Thermal, mechanical, and chemical properties of PBLG/PAA polymer blend films were studied by Differential Scanning Calorimetry (DSC, Thermogravimetric (TG Analysis, Tensile Tests, and measurements of Surface Contact Angles. The results revealed that the introduction of PAA could exert great effects on the structure and properties of the polypeptide films.

  2. Modification of magnetite coating formation in presence of alkaline acrylic acid

    In Indian PHWR's, the hot conditioning of primary heat transport system is carried out to form a protective magnetite coating on the inner surface of PHT system at the start up of the reactor and also after decontamination of PHT system to minimize the release of loose crud particulates and corrosion of the PHT system. An attempt has been made to modify the chemistry conditions for the formation of protective magnetite coating on CS coupons in a static autoclave at 523K to view its impact on the nature of the protectivity. In continuation of our efforts to modify the film with various organic additives like Glycerol, Ethylene glycol, PEG, in this paper the effect of acrylic acid on magnetite coating formation is discussed. The metal oxide powders synthesized by polymer combustion route in PVA, PEG and PAA resulted in nano crystallites. To see the effect of theses organics in reducing the crystallite sizes and improving the corrosion resistance behaviour in hydrothermal conditions the experiments are carried out. In presence of Acrylic acid (AA) at different concentrations (50, 100, 500ppm) at alkaline pH (LiOH -10.4 ) in static autoclave, magnetite coating is formed on CS coupons. The coupons were characterized by XRD, SEM, Raman and Electrochemical impedance and Potentiodynamic Anodic Polarization (PDAP) studies. The addition of acrylic acid results in smaller crystallite sizes and the crystallites look like thread bundles for 50ppm concentration of AA. PDAP studies indicate better film protectivity for magnetite coating formed in 50 ppm AA. Corrosion rate is observed to be less for CS coupons in presence of 50 and 100 ppm AA. The tendency for the film formed to dissolve is less for both 50 and 100 ppm AA developed coating in comparison to coating developed in LiOH alone. The impedance studies indicated the pore resistance of the film increased two fold and seven fold for 50 and 100 ppm acrylic acid case in comparison to simple LiOH case where as the charge

  3. Novel Routes for the Design of Poly((meth)acrylic acid) Containing Polymer Structures by Controlled Radical Polymerization

    Van Camp, W

    2007-01-01

    Easy preparation of specialty polymers containing poly((meth)acrylic acid) Poly(acrylic acid) (PAA) and poly(methacrylic acid) (PMAA) are well-known polymers in a high number of applications because of their pH-responsive nature, their hydrophylic characteristics and for their interaction with metal ions. PAA, high tech material An increasing part of high tech polymer materials introduce P(M)AA as segments in well-defined polymer structures. These can be block copolymers, polymer brushes, sta...

  4. Characterization of bioactive RGD peptide immobilized onto poly(acrylic acid) thin films by plasma polymerization

    Seo, Hyun Suk; Ko, Yeong Mu; Shim, Jae Won [Department of Dental Materials, School of Dentistry, MRC Center, Chosun University, Gwangju (Korea, Republic of); Lim, Yun Kyong; Kook, Joong-Ki [Department of Oral Biochemistry, School of Dentistry, Chosun University, Gwangju (Korea, Republic of); Cho, Dong-Lyun [School of Applied Chemical Engineering and Center for Functional Nano Fine Chemicals, Chonnam National University, Gwangju (Korea, Republic of); Kim, Byung Hoon, E-mail: kim5055@chosun.ac.kr [Department of Dental Materials, School of Dentistry, MRC Center, Chosun University, Gwangju (Korea, Republic of)

    2010-11-01

    Plasma surface modification can be used to improve the surface properties of commercial pure Ti by creating functional groups to produce bioactive materials with different surface topography. In this study, a titanium surface was modified with acrylic acid (AA) using a plasma treatment and immobilized with bioactive arginine-glycine-aspartic acid (RGD) peptide, which may accelerate the tissue integration of bone implants. Both terminals containing the -NH{sub 2} of RGD peptide sequence and -COOH of poly(acrylic acid) (PAA) thin film were combined with a covalent bond in the presence of 1-ethyl-3-3-dimethylaminopropyl carbodiimide (EDC). The chemical structure and morphology of AA film and RGD immobilized surface were investigated by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR), atomic force microscopy (AFM), and scanning electron microscopy (SEM). All chemical analysis showed full coverage of the Ti substrate with the PAA thin film containing COOH groups and the RGD peptide. The MC3T3-E1 cells were cultured on each specimen, and the cell alkaline phosphatase (ALP) activity were examined. The surface-immobilized RGD peptide has a significantly increased the ALP activity of MC3T3-E1 cells. These results suggest that the RGD peptide immobilization on the titanium surface has an effect on osteoblastic differentiation of MC3T3-E1 cells and potential use in osteo-conductive bone implants.

  5. Characterization of bioactive RGD peptide immobilized onto poly(acrylic acid) thin films by plasma polymerization

    Plasma surface modification can be used to improve the surface properties of commercial pure Ti by creating functional groups to produce bioactive materials with different surface topography. In this study, a titanium surface was modified with acrylic acid (AA) using a plasma treatment and immobilized with bioactive arginine-glycine-aspartic acid (RGD) peptide, which may accelerate the tissue integration of bone implants. Both terminals containing the -NH2 of RGD peptide sequence and -COOH of poly(acrylic acid) (PAA) thin film were combined with a covalent bond in the presence of 1-ethyl-3-3-dimethylaminopropyl carbodiimide (EDC). The chemical structure and morphology of AA film and RGD immobilized surface were investigated by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR), atomic force microscopy (AFM), and scanning electron microscopy (SEM). All chemical analysis showed full coverage of the Ti substrate with the PAA thin film containing COOH groups and the RGD peptide. The MC3T3-E1 cells were cultured on each specimen, and the cell alkaline phosphatase (ALP) activity were examined. The surface-immobilized RGD peptide has a significantly increased the ALP activity of MC3T3-E1 cells. These results suggest that the RGD peptide immobilization on the titanium surface has an effect on osteoblastic differentiation of MC3T3-E1 cells and potential use in osteo-conductive bone implants.

  6. Characterization of bioactive RGD peptide immobilized onto poly(acrylic acid) thin films by plasma polymerization

    Seo, Hyun Suk; Ko, Yeong Mu; Shim, Jae Won; Lim, Yun Kyong; Kook, Joong-Ki; Cho, Dong-Lyun; Kim, Byung Hoon

    2010-11-01

    Plasma surface modification can be used to improve the surface properties of commercial pure Ti by creating functional groups to produce bioactive materials with different surface topography. In this study, a titanium surface was modified with acrylic acid (AA) using a plasma treatment and immobilized with bioactive arginine-glycine-aspartic acid (RGD) peptide, which may accelerate the tissue integration of bone implants. Both terminals containing the -NH2 of RGD peptide sequence and -COOH of poly(acrylic acid) (PAA) thin film were combined with a covalent bond in the presence of 1-ethyl-3-3-dimethylaminopropyl carbodiimide (EDC). The chemical structure and morphology of AA film and RGD immobilized surface were investigated by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR), atomic force microscopy (AFM), and scanning electron microscopy (SEM). All chemical analysis showed full coverage of the Ti substrate with the PAA thin film containing COOH groups and the RGD peptide. The MC3T3-E1 cells were cultured on each specimen, and the cell alkaline phosphatase (ALP) activity were examined. The surface-immobilized RGD peptide has a significantly increased the ALP activity of MC3T3-E1 cells. These results suggest that the RGD peptide immobilization on the titanium surface has an effect on osteoblastic differentiation of MC3T3-E1 cells and potential use in osteo-conductive bone implants.

  7. Spectroscopic and density functional theory studies of trans-3-(trans-4-imidazolyl)acrylic acid

    Arjunan, V.; Remya, P.; Sathish, U.; Rani, T.; Mohan, S.

    2014-08-01

    The structural parameters, thermodynamic properties and vibrational frequencies of the optimised geometry of trans-3-(trans-4-imidazolyl)acrylic acid have been determined from B3LYP methods with 6-311++G** and cc-pVTZ basis sets. The effects of substituents (acrylyl group) on the imidazole vibrational frequencies are analysed. The vibrational frequencies of the fundamental modes of trans-3-(trans-4-imidazolyl)acrylic acid have been precisely assigned and analysed and the theoretical results are compared with the experimental vibrations. 1H and 13C NMR isotropic chemical shifts are calculated and the assignments made are compared with the experimental values. The energies of important MO’s of the compound are also determined from DFT method. The total electron density and electrostatic potential of the compound are determined by natural bond orbital analysis. Various reactivity and selectivity descriptors such as chemical hardness, chemical potential, softness, electrophilicity, nucleophilicity and the appropriate local quantities employing natural population analysis (NPA) are calculated.

  8. Antimicrobial and Thermal Properties of Metal Complexes of Grafted Fabrics with Acrylic Acid by Gamma Irradiation

    Cotton, cotton/PET blend and PET fabrics were treated against microbial effect by radiation - induced grafting of acrylic acid followed by metal complexation with some divalent transition metal ions Co (II), Ni (II) and Cu (II). The microbial resistance was evaluated by testing the mechanical properties of the treated fabrics after burring for one and two weeks in a moist soil reach with microorganisms. Also, the growth of microorganisms was examined by scanning electron microscope (SEM). Moreover, the effect of this treatment on the thermal decomposition behavior was investigated by thermogravimetric analysis (TGA). On the basis of microbial studies, it was found that the metal complexation of the grafted fabrics with acrylic acid enhanced the antimicrobial resistance of the fabrics and the antimicrobial resistance could be arranged according to the metal ions as follows: copper> nickel> cobalt. Also, the thermal stability of different fabrics could be arranged as follow: grafted fabrics complexed with Cu (II) > grafted fabrics complexed with Ni (II) > grafted fabrics complexed with Co (II)

  9. Controlled release of anti-diabetic drug Gliclazide from poly(caprolactone)/poly(acrylic acid) hydrogels.

    Bajpai, S K; Chand, Navin; Soni, Shweta

    2015-01-01

    Drug Gliclazide (Glz) has limited solubility and low bioavailability. In order to obtain a controlled release of this drug and to improve its bioavailability, the drug has been loaded into poly(caprolactone) (PCL)/poly(acrylic acid) (PAAc) hydrogels, prepared by free radical polymerization of acrylic acid in the presence of poly(caprolactone) in acetone medium using azo-isobutyronitrile as initiator and N,N' methylene bisacrylamide as cross-linking agent. The swelling behaviour of these hydrogels has been investigated in the physiological gastric and intestinal fluids to obtain an optimum composition suitable for delivery of a biologically active compound. The gels were loaded with anti-diabetic drug Glz and a detailed investigation of release of drug has been carried out. Various kinetic models have been applied on the release data. Finally, the Albino wistar rats were treated for Streptozotocin plus nicotinamide - induced diabetes using a Glz-loaded PCL/PAAc hydrogel. The results indicated a fair reduction in the glucose level of rats. PMID:26135033

  10. Radiation synthesis of chitosan beads grafted with acrylic acid for metal ions sorption

    Benamer, S., E-mail: benamers@yahoo.fr [Division of Nuclear Applications, Centre de Recherche Nucleaire d' Alger, BP-399 Alger-Gare (Algeria); Mahlous, M.; Tahtat, D.; Nacer-Khodja, A.; Arabi, M. [Division of Nuclear Applications, Centre de Recherche Nucleaire d' Alger, BP-399 Alger-Gare (Algeria); Lounici, H.; Mameri, N. [Ecole Nationale Polytechnique d' El-Harrach Alger (Algeria)

    2011-12-15

    Radiation-induced grafting of acrylic acid onto chitosan beads was performed in solution at a dose rate of 20.6 Gy/min of cobalt-60 gamma rays. The effect of absorbed dose on grafting yield was investigated. The characterization of the grafted material was performed by FTIR spectroscopy and the swelling measurements at different pHs. The grafting yield increased with the increase in dose, it reached 80% at 40 kGy irradiation dose. The removal of Pb and Cd ions from aqueous solutions was investigated with both ungrafted and grafted chitosan beads. The sorption behavior of the sorbents was examined through pH, kinetics and equilibrium measurements. Grafted chitosan beads presented higher sorption capacity for both metal ions than unmodified chitosan beads. - Highlights: > Pb and Cd ions are removed from aqueous solution by adsorption on chitosan beads. > Crosslinking process improves chemical stability of chitosan beads. > Radiation grafting of acrylic acid onto chitosan improves its metal adsorption capacity. > Increase in grafting degree enhances the adsorption capacity of the material. > Gamma radiation is a powerful tool for an accurate control of the grafting yield.

  11. Synthesis of ion exchange membrane by radiation grafting of acrylic acid onto polyethylene

    Radiation grafting of vinyl monomers onto polymer films has been extensively studied by many workers. In the preirradiation method of grafting a polymer substrate is activated by irradiation (either in the presence or absence of oxygen) and subsequently allowed to react with a monomer. The preirradiation method was utilized in this study to synthesize an ion exchange membrane useful for a battery separator by grafting acrylic acid onto polyethylene film. The battery separator should be chemically and thermally stable, sufficiently durable in electrolyte as well as highly electrically conductive. Membranes made from regenerated cellulose, e.g., cellophane, have long been used as a separator in the batteries with alkaline electrolyte, such as silver oxide primary cell. However, it has poor durability, as short as one year, due to breakdown of the membrane during operation or storing. The acrylic acid-grafted polyethylene film was found to be quite useful for a separator in the alkaline batteries. This membrane has a high electric conductivity and an excellent durability. (author)

  12. Radiation synthesis of chitosan beads grafted with acrylic acid for metal ions sorption

    Radiation-induced grafting of acrylic acid onto chitosan beads was performed in solution at a dose rate of 20.6 Gy/min of cobalt-60 gamma rays. The effect of absorbed dose on grafting yield was investigated. The characterization of the grafted material was performed by FTIR spectroscopy and the swelling measurements at different pHs. The grafting yield increased with the increase in dose, it reached 80% at 40 kGy irradiation dose. The removal of Pb and Cd ions from aqueous solutions was investigated with both ungrafted and grafted chitosan beads. The sorption behavior of the sorbents was examined through pH, kinetics and equilibrium measurements. Grafted chitosan beads presented higher sorption capacity for both metal ions than unmodified chitosan beads. - Highlights: → Pb and Cd ions are removed from aqueous solution by adsorption on chitosan beads. → Crosslinking process improves chemical stability of chitosan beads. → Radiation grafting of acrylic acid onto chitosan improves its metal adsorption capacity. → Increase in grafting degree enhances the adsorption capacity of the material. → Gamma radiation is a powerful tool for an accurate control of the grafting yield.

  13. Protein absorption and fouling on poly(acrylic acid)-graft-polypropylene microfiltration membrane

    Liu, Yanjun; Ma, Huiying; Lv, Chunying; Yang, Jia; Fu, Xueqi

    2009-07-01

    A series of pH-sensitive poly (acrylic acid)-graft-polypropylene hollow fiber microfiltration membranes were prepared by UV-photo-irradiation. Bovine serum albumin (BSA) was chosen as the model protein to investigate its absorption and fouling behaviors on membranes. The results showed that the hydrophilicity of grafted membrane was improved by poly(acrylic acid) chains with parts of membrane pores blocked. The grafted membranes were markedly pH-dependent on the water permeability as pH was altered from 1 to 11. The zeta potential of grafted membranes calculated by streaming potential was negative in most pH range. Electrostatic interaction energy calculated by DLVO theory showed the electric interaction force between grafted membrane and BSA was attractive. With the rise of grafting degree, the electric attractive force between grafted membrane and BSA increased as pH=3 and decreased as pH=8, while it kept basically unchanged as pH=4.7. As a result, most serious fouling was observed as pH=4.7. Grafted membranes had a lower BSA absorption and better antifouling behavior as pH=8, while the opposite result was revealed as pH=3. In conclusion, the absorption and fouling behavior of BSA on membranes was pH-dependent due to the pH-dependence of membrane charge, and the conformation of BSA and grafting chains.

  14. Investigation of small molecular weight poly(acrylic acid) adsorption on γ-alumina

    Liu, Lei; Luo, Shi-Zhong [College of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065 (China); Wang, Bin, E-mail: bin_wang@scu.edu.cn [College of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065 (China); Guo, ZhanHu [Chemical and Biomolecular Engineering Department, University of Tennessee, Knoxville, TN 37996 (United States)

    2015-08-01

    Highlights: • Small molecular weight poly(acrylic acid) incorporated on γ-alumina. • PAA adsorbed primarily on outer surface of alumina at low pH. • PAA infiltrated inside alumina pore at high pH. • Polymer chain reptation motion during the infiltration. - Abstract: The interactions between poly(acrylic acid) (PAA) and alumina have been widely investigated. In this study, the pattern of small molecular weight PAA (M{sub W} 3000) interaction with γ-alumina has been dissected. The alumina/PAA hybrids were prepared at pH 4.0, 5.5, and 7.0, respectively. Nitrogen absorption–desorption analysis, Fourier transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and elemental analysis were conducted to illustrate the characteristics of the hybrids. At pH 4.0, the coiled PAA conformation yielded polymer adsorption primarily on alumina outer surface. At higher pH values, the more stretched PAA molecules were able to infiltrate inside the alumina pores. The phenomenon is explained by the polymer chain reptation motion model. Coiled polymer chains are not oriented enough to penetrate the oxide pore channels. In contrary, stretched polymer chains are more likely to move along the pore channels.

  15. Investigation of small molecular weight poly(acrylic acid) adsorption on γ-alumina

    Highlights: • Small molecular weight poly(acrylic acid) incorporated on γ-alumina. • PAA adsorbed primarily on outer surface of alumina at low pH. • PAA infiltrated inside alumina pore at high pH. • Polymer chain reptation motion during the infiltration. - Abstract: The interactions between poly(acrylic acid) (PAA) and alumina have been widely investigated. In this study, the pattern of small molecular weight PAA (MW 3000) interaction with γ-alumina has been dissected. The alumina/PAA hybrids were prepared at pH 4.0, 5.5, and 7.0, respectively. Nitrogen absorption–desorption analysis, Fourier transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and elemental analysis were conducted to illustrate the characteristics of the hybrids. At pH 4.0, the coiled PAA conformation yielded polymer adsorption primarily on alumina outer surface. At higher pH values, the more stretched PAA molecules were able to infiltrate inside the alumina pores. The phenomenon is explained by the polymer chain reptation motion model. Coiled polymer chains are not oriented enough to penetrate the oxide pore channels. In contrary, stretched polymer chains are more likely to move along the pore channels

  16. Surface properties of ionomers based on styrene-b-acrylic acid copolymers obtained by copolymerization in emulsion

    Surface properties of styrene-b-acrylic acid copolymers obtained in emulsion and suitable ionomers before and after UV-irradiation were studied by measurements of contact angles and FTIR-ATR spectroscopy. The research focused on the influence of different content of carboxylic acid groups in copolymers, of various types and contents of alkali metal salts in ionomers and of cesium acrylate or methacrylate in ionomers on hydrophilicity of the surfaces of these samples and the course of photodegradation in them. Hydrophilicity of initial copolymer surfaces was higher than this of polystyrene as a result of presence of carboxylic acid groups, which also made the surfaces of these copolymers more sensitive to UV-irradiation. Hydrophilicity of the surfaces of ionomers containing cesium acrylates depended on the content of cesium salt in the samples. The course of ionomer photooxidation was also dependent on the content of this salt. The surface of ionomer containing cesium methacrylate was more polar than this of ionomer containing cesium acrylate. Styrene-based ionomers containing 3.7 mol% of various alkali metal acrylates had less polar surfaces than initial copolymer and they were also more resistant to UV-irradiation in comparison to the initial copolymer. Copolymers obtained in emulsion and suitable ionomers had more polar surfaces and they were more sensitive to UV-light compared to copolymers obtained in bulk and their ionomers.

  17. Acrylic and Methacrylic Acids Obtaining by Gas-Phase Aldol Condensation of Carbonyl Compounds on B2O3?P2O5?WO3?V2O5/SiO2 Catalysts

    Nebesnyi, Roman; Petelka, Oksana; Shpyrka, Iryna

    2013-01-01

    Prospects of acrylic acid obtaining by acetic acid aldol condensation with formaldehyde are considered. Complex oxide catalysts of the process have been developed. It is shown that raw materials costs in case of acrylic acid production by the condensation method are commeasurable with those in case of its production by oxidation method (main industrial method of acrylic acid production).This method of acrylic acid obtaining may be used as an alternative and enables diversifying the raw materi...

  18. Synthesis and characterization of organometallic copolymers of acrylic acid g-polyethylene, with Mo, Fe, Co, Zn and Ni

    In this study, the preparation of a series of low density polyethylenes grafted with acrylic acid is presented. The grafting reactions were initiated by different doses of γ radiation; it was observed that grafting increased with the doses of radiation. The prepared copolymers were coordinated with different metals, as Mo, Fe, Co, Zn and Ni. The amount of metal supported on the polymer was determined by atomic absorption. Infrared spectroscopy and thermogravimetric analysis confirmed the metal chelation on the graft copolymer. The film surfaces were observed by scanning electron microscopy. positron annihilation spectroscopy revealed a decrease on the free volume in the low density polyethylene after the grafting with acrylic acid. (Author)

  19. Poly (acrylic acid sodium) grafted carboxymethyl cellulose as a high performance polymer binder for silicon anode in lithium ion batteries

    Liangming Wei; Changxin Chen; Zhongyu Hou; Hao Wei

    2016-01-01

    The design of novel binder systems is required for the high capacity silicon (Si) anodes which usually undergo huge volume change during the charge/discharge cycling. Here, we introduce a poly (acrylic acid sodium)-grafted-carboxymethyl cellulose (NaPAA-g-CMC) copolymer as an excellent binder for Si anode in lithium ion batteries (LIBs). The NaPAA-g-CMC copolymer was prepared via a free radical graft polymerization method by using CMC and acrylic acid as precursors. Unlike the linear, one-dim...

  20. The pH-responsive behaviour of poly(acrylic acid) in aqueous solution is dependent on molar mass.

    Swift, T; Swanson, L.; Geoghegan, M; Rimmer, S.

    2016-01-01

    Fluorescence spectroscopy on a series of aqueous solutions of poly(acrylic acid) containing a luminescent label showed that polymers with molar mass, Mn < 16.5 kDa did not exhibit a pH responsive conformational change, which is typical of higher molar mass poly(acrylic acid). Below this molar mass, polymers remained in an extended conformation, regardless of pH. Above this molar mass, a pH-dependent conformational change was observed. Diffusion-ordered nuclear magnetic resonance spectroscopy ...

  1. ABS polymer electroless plating through a one-step poly(acrylic acid) covalent grafting.

    Garcia, Alexandre; Berthelot, Thomas; Viel, Pascal; Mesnage, Alice; Jégou, Pascale; Nekelson, Fabien; Roussel, Sébastien; Palacin, Serge

    2010-04-01

    A new, efficient, palladium- and chromium-free process for the electroless plating of acrylonitrile-butadiene-styrene (ABS) polymers has been developed. The process is based on the ion-exchange properties of poly(acrylic acid) (PAA) chemically grafted onto ABS via a simple and one-step method that prevents using classical surface conditioning. Hence, ABS electroless plating can be obtained in three steps, namely: (i) the grafting of PAA onto ABS, (ii) the copper Cu(0) seeding of the ABS surface, and (iii) the nickel or copper metallization using commercial-like electroless plating bath. IR, XPS, and SEM were used to characterize each step of the process, and the Cu loading was quantified by atomic absorption spectroscopy. This process successfully compares with the commercial one based on chromic acid etching and palladium-based seed layer, because the final metallic layer showed excellent adhesion with the ABS substrate. PMID:20361751

  2. Use of acrylic acid in the synthesis of molecularly imprinted polymers for the analysis of cyproheptadine

    Feas, Xesus [Analytical Chemistry, Nutrition and Bromatology, Campus Lugo, University of Santiago de Compostela. E-27002, Lugo, Galiza (Spain); Fente, Cristina A. [Analytical Chemistry, Nutrition and Bromatology, Campus Lugo, University of Santiago de Compostela. E-27002, Lugo, Galiza (Spain)], E-mail: cfente@lugo.usc.es; Hosseini, S. Vali [Analytical Chemistry, Nutrition and Bromatology, Campus Lugo, University of Santiago de Compostela. E-27002, Lugo, Galiza (Spain); Seijas, Julio A. [Organic Chemistry, Campus Lugo, University of Santiago de Compostela. Aptdo 280, E-27080, Lugo (Spain); Vazquez, Beatriz I.; Franco, Carlos M.; Cepeda, Alberto [Analytical Chemistry, Nutrition and Bromatology, Campus Lugo, University of Santiago de Compostela. E-27002, Lugo, Galiza (Spain)

    2009-03-01

    The synthesis and comparative characterization of molecularly imprinted polymers (MIP{sub s}) with cyproheptadine (CYP), using two different monomers, acrylic acid (AA) and methacrylic acid (MAA), are described. Polyacids (PA) [poly(methacrylic acid) (PMAA) and poly(acrylic acid) (PAA)] were obtained by the radical polymerization of MAA and AA, respectively, in dichloromethane as the porogen solvent-imprinted medium. The non-covalent imprinting process was performed via thermal decomposition of an azo-initiator at 60 deg. C, using ethylene glycol dimethacrylate as the cross-linker and 2,2'-azobis(2-methylpropionitrile) as the initiator. The selectivities of MIP{sub s} and NIP{sub s} particles were evaluated in binding experiments of the four synthesized polymeric materials (MIP{sub aa}, MIP{sub maa}, NIP{sub maa} and NIP{sub aa}) with CYP. The effects of monomers on: a) the surface morphology, b) the binding capacity and c) the swelling properties of imprinted and non-imprinted polymers were studied and are presented here. Polymer material morphology was assessed with scanning electron microscopy (SEM). This revealed differences in monomer function, depending on which one was employed, as well as differences in function when polymerization occurred in the presence of template or without it. Non-specific retention of the template to NIP{sub s} was higher for NIP{sub s}-PAA polymers than for NIP{sub s}-PMAA materials. In terms of specific binding ({delta}Q = Q{sub MIP} - Q{sub NIP}), MIP{sub maa} showed the greatest value (53.47%) in comparison with MIP{sub aa} (50.07%)

  3. Electron-beam induced RAFT-graft polymerization of poly(acrylic acid) onto PVDF

    This paper explores for the first time the post-radiation-induced-graft polymerization on solid substrate using reversible addition-fragmentation transfer (RAFT) mechanism. Radiation-induced graft polymerization onto polymers is a potentially interesting technique to create easily new materials from highly resistant polymers, e.g. surface graft polymerization of acrylic acid (AA) onto poly(vinylidene difluoride) (PVDF) improves its surface properties without losing its excellent mechanical properties. As a consequence of the radical nature of the polymerization processes it is difficult to control molecular weight of grafted chains, and therefore design and standardize the properties of the final product. RAFT polymerization is a suitable method to obtain monodisperse polymers. The ability of the RAFT agents to control the polymer chain length could be an interesting approach to improve the grafted polymers obtained by post-radiation-induced-graft polymerization technique. In this way, graft polymerization of AA onto electron-beam irradiated α-PVDF was performed using trithiocarbonic acid bis(1-phenylethyl) ester as a RAFT agent to control the radical polymerization. We studied several grafting parameters such as solvent, monomer concentration and grafting time in order to achieve a poly(acrylic acid) (PAA) layer onto PVDF surface. Acetic acid was found to be the best solvent for many reasons, as to drive graft polymerization mainly to the polymer surface, complete solubility and stability of all reactants. Hydrolysis of PAA chains was also studied in order to remove the trithiocarbonate functionality from the grafted polymer. A mild chemical condition was achieved in order to have thiol groups that were detected onto the modified PVDF by specific enzymatic reaction

  4. Electron-beam induced RAFT-graft polymerization of poly(acrylic acid) onto PVDF

    Grasselli, M.; Betz, N.

    2005-07-01

    This paper explores for the first time the post-radiation-induced-graft polymerization on solid substrate using reversible addition-fragmentation transfer (RAFT) mechanism. Radiation-induced graft polymerization onto polymers is a potentially interesting technique to create easily new materials from highly resistant polymers, e.g. surface graft polymerization of acrylic acid (AA) onto poly(vinylidene difluoride) (PVDF) improves its surface properties without losing its excellent mechanical properties. As a consequence of the radical nature of the polymerization processes it is difficult to control molecular weight of grafted chains, and therefore design and standardize the properties of the final product. RAFT polymerization is a suitable method to obtain monodisperse polymers. The ability of the RAFT agents to control the polymer chain length could be an interesting approach to improve the grafted polymers obtained by post-radiation-induced-graft polymerization technique. In this way, graft polymerization of AA onto electron-beam irradiated α-PVDF was performed using trithiocarbonic acid bis(1-phenylethyl) ester as a RAFT agent to control the radical polymerization. We studied several grafting parameters such as solvent, monomer concentration and grafting time in order to achieve a poly(acrylic acid) (PAA) layer onto PVDF surface. Acetic acid was found to be the best solvent for many reasons, as to drive graft polymerization mainly to the polymer surface, complete solubility and stability of all reactants. Hydrolysis of PAA chains was also studied in order to remove the trithiocarbonate functionality from the grafted polymer. A mild chemical condition was achieved in order to have thiol groups that were detected onto the modified PVDF by specific enzymatic reaction.

  5. Decolourization performance in C. I. Vat Yellow 1 aqueous suspension using hydrophobically modified poly(acrylic acid).

    Chen, J; Chen, M C

    2011-01-01

    A series of hydrophobically modified poly(acrylic acid) (PAA), poly(2-phenoxyethyl acrylate-co-acrylic acid) (poly(PHEA-co-AA)), have been synthesized and characterized by Ubbelohde type viscometry, Nuclear Magnetic Resonance (1H NMR) spectrometry and Differential Scanning Calorimetry (DSC). The shear thinning Non-Newtonian fluid behavior of their aqueous solution and the dependence on pH and hydrophobic group contents were found through apparent viscosity and rheological property investigating. Decolourization performance in C. I. Vat Yellow 1 aqueous suspension was evaluated through visible absorbance data. Decolourization performance of hydrophobically associated polymer indicates two times better than that of PAA. The quantitative relationship was mainly studied. PMID:21866762

  6. Chelation in metal intoxication XXX: α-mercapto-β-aryl acrylic acids as antidotes to cadmium toxicity

    α-Mercapto-β-(2-furyl) acrylic acid (MFA), α-mercapto-β-(2-hydroxyphenyl) acrylic acid (MHA), β-1,2-phenylene di-α-mercaptoacrylic acid (1,2-PDMA) and β-l,4-phenylene di-α-mercapto acrylic acid (1,4-PDMA) were compared to sodium N-benzyl-D-glucamine dithiocarbamate (NBG-DTC) an effective cadmium chelator, for their ability to mobilize Cd and influence the Cd induced tissue metallothionein (MT) in rats administered 109CdCl2, 72 hr earlier. MFA was almost as effective as NBG-DTC but more effective than MHA in enhancing urinary and faecal excretion of Cd, reducing tissue and blood levels of Cd and in lowering Cd induced increase in hepatic and renal MT contents. 1,2-PDMA and l,4-PDMA were effective only in reducing the hepatic burden of Cd. The results do not indicate any direct relationship between the efficacy of α-mercapto-β-aryl acrylic acids to decorporate body Cd and their lipophilic-hydrophilic character or number-arrangement of their sulfhydryl groups. (author)

  7. UV-induced graft polymerization of acrylic acid in the sub-micronchannels of oxidized PET track-etched membrane

    Korolkov, Ilya V.; Mashentseva, Anastassiya A.; Güven, Olgun; Taltenov, Abzal A.

    2015-12-01

    In this article, we report on functionalization of track-etched membrane based on poly(ethylene terephthalate) (PET TeMs) oxidized by advanced oxidation systems and by grafting of acrylic acid using photochemical initiation technique for the purpose of increasing functionality thus expanding its practical application. Among advanced oxidation processes (H2O2/UV) system had been chosen to introduce maximum concentration of carboxylic acid groups. Benzophenone (BP) photo-initiator was first immobilized on the surfaces of cylindrical pores which were later filled with aq. acrylic acid solution. UV-irradiation from both sides of PET TeMs has led to the formation of grafted poly(acrylic acid) (PAA) chains inside the membrane sub-micronchannels. Effect of oxygen-rich surface of PET TeMs on BP adsorption and subsequent process of photo-induced graft polymerization of acrylic acid (AA) were studied by ESR. The surface of oxidized and AA grafted PET TeMs was characterized by UV-vis, ATR-FTIR, XPS spectroscopies and by SEM.

  8. Electromechanical reliability of flexible transparent electrodes during and after exposure to acrylic acid

    The effect of deposition temperature on pulsed laser deposition (PLD) fabricated flexible transparent electrodes subjected to mechanical loading, after exposure to acrylic acid, and the combined effect of fatigue and corrosion on sputter-deposited polyester-based indium tin oxide (ITO) films are both investigated in this study. Acrylic acid containing pressure sensitive adhesives, which are commonly used in various flexible device stacks, can corrode the ITO film. In addition, fatigue due to cyclic loading can lead to film cracking. The combined effect of fatigue and corrosion can lead to catastrophic failure of the system. We found that PLD-produced ITO on polyethylene naphthalate samples deposited at 150 °C performs better than samples deposited at 50 °C under uniaxial mechanical loading. They were found to exhibit higher crack onset strain than their 50 °C counterparts. However, they were observed to be more sensitive to increasing acid concentrations. Scanning electron microscopy images show a larger number of adhesive cracks on the surfaces of the 150 °C-deposited samples than the 50 °C-deposited samples. Atomic force microscopy results reveal that the increased temperature causes a significant increase in surface roughness which may affect the corrosion behavior of the ITO film. Furthermore, in situ electrical resistance measurements and crack density analysis suggest that the combination of fatigue and corrosion can cause film failure at low strains, less than those needed for failure with no corrosion. For example, at 0.9% applied strain and 500,000 cycles, the crack density under fatigue–corrosion is 1.7 times that of the fatigue-only case. - Highlights: ► ITO films were deposited on polymers with PLD or magnetron sputtering. ► The combination of fatigue and corrosion was investigated using a custom apparatus. ► Adhesion and film roughness played roles in the fatigue-corrosion behavior

  9. A new and direct synthesis of lactic acid from acrylic acid using an excimer laser with high intensity

    A new and direct method of XeF (351 nm) laser irradiation of acrylic acid 1 solution containing H2O2 are described for the chemical synthesis of lactic acid 2. Increase in the yield strongly depended on the irradiation dose and H2O2 feeding rate, and the formation of 2 showed the quantum yield, 0.3, and the selectivity, 50%, at the maximum yield. Product analysis indicated that OH radicals formed with high density by the laser-photolysis of H2O2 are equally bonded to the carbons of α- and β-positions of 1 to produce 2 and 3-hydroxy propanoic acid with ratio of 1 to 1. (author)

  10. A facile one pot strategy for the synthesis of well-defined polyacrylates from acrylic acid via RAFT polymerization.

    Li, Qianbiao; Wang, Taisheng; Dai, Jingwen; Ma, Chao; Jin, Bangkun; Bai, Ruke

    2014-03-28

    A facile one pot strategy for the preparation of linear and hyperbranched polyacrylates has been successfully developed by the combination of in situ esterification of acrylic acid with halogenated compounds promoted by 1,1,3,3-tetramethylguanidine (TMG) and RAFT polymerization. PMID:24534953

  11. Structure-function properties of amylose-oleic acid inclusion complexes grafted with poly(methyl acrylate)

    Spherulites, produced by steam jet-cooking high-amylose starch and oleic acid, were grafted with methyl acrylate, both before and after removal of un-complexed amylopectin. For comparison, granular high-amylose corn starch was graft polymerized in a similar manner. The amount of grafted and ungrafte...

  12. Comparison of various models to describe the charge-pH dependence of poly(acrylic acid)

    Lützenkirchen, J.; Male, van J.; Leermakers, F.A.M.; Sjöberg, S.

    2011-01-01

    The charge of poly(acrylic acid) (PAA) in dilute aqueous solutions depends on pH and ionic strength. We report new experimental data and test various models to describe the deprotonation of PAA in three different NaCl concentrations. A simple surface complexation approach is found to be very success

  13. Adsorptive features of poli(acrylic acid-co-hydroxyapatite) composite for UO22+

    The copolymer of poli(acrylic acid-co-hydroxyapatite) (PAA-HAP) was prepared and characterized by means of FT-IR and SEM analysis. The adsorptive features of PAA-HAP for UO22+ was studied as a function of pH, adsorbent dosage, initial metal ion concentration and temperature. The adsorption isotherm data fitted well to the Langmuir isotherm model. The adsorbed UO22+ can be desorbed effectively by 0.1 M HNO3. The maximum adsorption capacities for UO22+ of the dry PAA-HAP was 1.86 x 10-4 mol/g. The high adsorption capacity and kinetics results indicate that PAA-HAP can be used as an alternative adsorbent to remove UO22+ from aqueous solution. (author)

  14. Cascade enzymatic catalysis in poly(acrylic acid) brushes-nanospherical silica for glucose detection.

    Zhao, Yan; Wang, Ying; Zhang, Xiaobin; Kong, Rongmei; Xia, Lian; Qu, Fengli

    2016-08-01

    The ultrasensitive monitoring of glucose with a fast and accurate method is significant in potential therapeutics and optimizes protein biosynthesis. Incorporation of enzyme into matrix is considered as promising candidates for constructing highly sensitive glucose-responsive systems. In this study, three-dimensional poly(acrylic acid) brushes-nanospherical silica (PAA-nano silica) with high amplification capability and stability were used to covalently immobilize bienzymes for cascade enzymatic catalysis. The major advantages of PAA-nano silica-bienzyme co-incorporation is that the enzymes are proximity distribution, and such close confinement both minimized the diffusion of intermediates among the enzymes in the consecutive reaction and improve the utilization efficiency of enzymes, thereby enhancing the overall reaction efficiency and specificity. Thus, this present bienzymatic biosensor shows robust signal amplification and ultrasensitivity of glucose-responsive properties with a detection limit of 0.04μM. PMID:27216683

  15. Study on swelling behaviour of hydrogel based on acrylic acid and pectin from dragon fruit

    Abdullah, Mohd Fadzlanor; Lazim, Azwani Mat

    2014-09-01

    Biocompatible hydrogel based on acrylic acid (AA) and pectin was synthesized using gamma irradiation technique. AA was grafted onto pectin backbone that was extracted from dragon fruit under pH 3.5 and extracts and ethanol ratios (ER) 1:0.5. The optimum hydrogel system with high swelling capacity was obtained by varying the dose of radiation and ratio of pectin:AA. FTIR-ATR spectroscopy was used to verify the interaction while thermal properties were analyzed by TGA and DSC. Swelling studies was carried out in aqueous solutions with different pH values as to determine the pH sensitivity. The results show that the hydrogel with a ratio of 2:3 (pectin:AA) and 30 kGy radiation dose has the highest swelling properties at pH of 10.

  16. Grafting of acrylic acid onto polypropylene films irradiated with argon ions

    Polypropylene (PP) foils were irradiated with 100 keV energy Argon ions at different fluences ranging from 1012 up to 2 x 1015 cm-2 and then grafted with acrylic acid (AA). The grafting yield was measured by weight difference and the structural changes on the films were analysed using Fourier transform infrared spectroscopy (FTIR). Different parameters that determined the grafting process such us fluence, grafting time and monomer concentration were analysed. The grafting reached an optimum value at 79% in aqueous solution at 30 min grafting time. The grafting yield as a function of the ion fluence plot, presented a maximum value, as previously found in a study of heavy beam on polymers

  17. Poly-Acrylic Acid Derivatives as Diesel Flow Improver for Paraffin-Based Daqing Diesel

    Cuiyu Jiang; Ming Xu; Xiaoli Xi; Panlun Qi; Hongyan Shang

    2006-01-01

    Since the diesel products from paraffin-based Daqing crude oil showed low sensitivity to certain commercial diesel pour point depressant (PPDs) that resulted from the high content of paraffin, certain poly-acrylic acid derivatives (PADE) with-COOR,-COOH,-CONHR, and -COO-NH3+R groups by molecular design on the mechanics of diesel; PPDs were synthesized and evaluated as cold flow improver for Daqing 0# diesel in this paper. The pure PADE was superior to the commercial PPDs and displayed a substantial ability of wax crystals dispersion. There was a synergistic effect among the PADE and T1804 and secondary amine. The synergism clearly improved the low temperature performance of Daqing diesel products and could reduce the cold filter plugging point of 0# diesel by 6-7 ℃.

  18. Michael-type addition of azoles of broad-scale acidity to methyl acrylate

    Krzysztof Z. Walczak

    2011-02-01

    Full Text Available An optimisation of Michael-type addition of azole derivatives of broad-scale acidity – ranging from 5.20 to 15.00 pKa units – namely 4-nitropyrazole, 3,5-dimethyl-4-nitropyrazole, 4(5-nitroimidazole, 4,5-diphenylimidazole, 4,5-dicyanoimidazole, 2-methyl-4(5-nitroimidazole, 5(4-bromo-2-methyl-4(5-nitroimidazole and 3-nitro-1,2,4-triazole to methyl acrylate as an acceptor was carried out. The optimisation process involved the use of an appropriate basic catalyst (DBU, DIPEA, NaOH, NaH, TEDA, a donor/base/acceptor ratio and the reaction temperature. The reactions were performed in DMF as solvent. Target Michael adducts were obtained in medium to excellent yields. Importantly, for imidazole and 1,2,4-triazole derivatives, no corresponding regioisomers were obtained.

  19. Thermal degradation of biopolymer binders: the example of starch-poly(acrylic acid

    B. Grabowska

    2010-01-01

    Full Text Available To characterise a polymer, it is of fundamental importance to determine its parameters, like the temperatures of destruction, vitrification, melting point, specific mass losses or polymorphic transformations, which frequently determine the quality of the product and its applications. Thermal analyses were conducted of samples of a biopolymer binder: a starch-poly(acrylic acid composition and a moulding sand with a biopolymer binder previously hardened with microwaves. In order to determine the thermal stability of the examined samples by determining the destruction temperature and the thermal effects of transformations taking place during heating, FTIR spectroscopy and thermal analysis (DSC, DTG, TG methods were used. In addition, volatile products of degradation were analysed using the thermogravimetry (TG method coupled online with mass spectrometry (MS. These examinations were also aimed at identifying the changes that can take place in the moulding sand when it comes into contact with liquid metal.

  20. Property and AFM analysis of copolymer from konjac graft acrylic acid by irradiation

    The water absorption property and construction of konjac glucomannon, copolymer and regenerated copolymer demonstrated by Atomic Force Microscopy(AFM)was studied in this paper. Result showed that the copolymer was 887.8 times distilled water and the water absorption of konjac glucomannan was only 60 times. The biggest water absorption speed of distilled water was 64.7 g.g-1. min-1.The water reserving percent was 92% at room temperature after 24 h from fully water absorbing.The largest second tap water absorption was 366 times which was higher than the first. The AFM images indicated konjac grafts acrylic acid and hydrophilic sturcture comes into being. During the course of regeneration the dimensional sturcture of the copolymer was changed to more regularly.So the water absorption of copolymer was higher than konjac and regenerater's was higher than copolymer. (authors)

  1. Poly(acrylic acid)-stabilized colloidal gold nanoparticles: synthesis and properties

    Combining the intriguing optical properties of gold nanoparticles with the inherent physical and dynamic properties of polymers can give rise to interesting hybrid nanomaterials. In this study, we report the synthesis of poly(acrylic acid) (PAA)-capped gold nanoparticles. The polyelectrolyte-wrapped gold nanoparticles were fully characterized and studied via a combination of techniques, i.e. UV-vis and infrared spectroscopy, dark field optical microscopy, SEM imaging, dynamic light scattering and zeta potential measurements. Although PAA-capped nanoparticles have been previously reported, this study revealed some interesting aspects of the colloidal stability and morphological change of the polymer coating on the nanoparticle surface in an electrolytic environment, at various pH values and at different temperatures.

  2. Dielectric properties of solution-grown-undoped and acrylic-acid-doped ethyl cellulose

    P K Khare; Sandeep K Jain

    2000-02-01

    Dielectric capacities and losses were measured, in the temperature (50–170°C) and frequency (01–100 kHz range), for undoped and acrylic acid (AA) doped ethyl cellulose (EC) films (thickness about 20 m) with progressive increase in the concentration of dopant in the polymer matrix. The variation of capacity with temperature is attributed to thermal expansion in the lower temperature region to the orientation of dipolar molecules in the neighbourhood of glass transition temperature () and random thermal motion of molecules above . The dielectric losses exhibit a broad peak. Doping with AA is found to affect the magnitude and position of the peak. AA is found to have a two-fold action. Firstly, it enhances the chain mobility and secondly, it increases the dielectric loss by forming charge transfer complexes.

  3. Superabsorbent Prepared by Radiation Induced Graft Copolymerization of Acrylic Acid onto Cassava Starch. Chapter 18

    Superabsorbent was synthesized by radiation induced graft polymerization of acrylic acid onto cassava starch. Parameters such as the absorbed dose and the amount of monomer were investigated in order to determine the optimum conditions for the grafting polymerization. Water retention, germination percentage, and germination energy were also determined in order to evaluate the possibility of superabsorbent in agricultural applications, especially in arid regions. The graft copolymer was characterized by the Fourier transform infrared spectroscopy (FTIR). Results indicated that the sand mixed with 0.1% wt superabsorbent could absorb more water than the sand without superabsorbent. The germination energy of corn seeds mixed with 0.5% superabsorbent was obviously higher than those without superabsorbent. These experimental results showed that the superabsorbent has considerable effects on seed germination and the growth of young plants. (author)

  4. Grafting of acrylic acid on etched latent tracks induced by swift heavy ions on polypropylene films

    In order to continue with a systematic study that include different polymers and monomers, the residual active sites produced by heavy ion beams, that remain after the etching process, were used to start the grafting process. To produce tracks, foils of polypropylene (PP) were irradiated with 208Pb of 25.62 MeV/n. Then, these were etched and grafted with acrylic acid (AA) monomers. Experimental curves of grafting yield as a function of grafting time with the etching time as a parameter were measured. Also, the grating yield as a function of the fluence and etching time was obtained. In addition, the permeation of solutions, with different pH, through PP grafted foils was measured

  5. Preparation of porous chitosan-poly(acrylic acid)-calcium phosphate hybrid nanoparticles via mineralization

    CHEN ChangJing; DENG Yu; YAN ErYun; HU Yong; JIANG XiQun

    2009-01-01

    In this work,the preparation of chitosan-poly(acrylic acid)-calcium phosphate hybrid nanoparticles (CS-PAA-CaP NP) based on the mineralization of calcium phosphate (CAP) on the surface of chitosan-poly (acrylic acid) nanoparticles (CS-PAA NPs) was reported. CS-PAA-CaP NPs were achieved by directly adding ammonia to the aqueous solution of CS-PAA nanoparticles or by thermal decomposition of urea in the aqueous solution of CS-PAA nanoparticles,resulting in the mineralization of CaP on the surface of CS-PAA NPs. Through these two routes,especially using urea as a pH-regulator,the precipitation of CS-PAA NPs,a common occurrence in basic environment,was avoided. The size,morphology and ingredient of CS-PAA-CaP hybrid nanoparticles were characterized by dynamic light scattering (DLS),transmission electron microscope (TEM),scanning electron microscope (SEM),thermogravimetry analysis (TGA) and X-ray diffractometer (XRD). When urea was used as the pH regulator to facilitate the mineralization during the thermal urea decomposition procedure,regular CS-PAA-CaP hybrid nanoparticles with a porosity-structural CaP shells and 400-600 nm size were obtained. TGA result revealed that the hybrid NPs contained approximately 23% inorganic component,which was consistent with the ratio of starting materials. The XRD spectra of hybrid nanoparticles indicated that dicalcium phosphate (DCP:CaHPO4) crystal was a dominant component of mineralization.The porous structure of the CS-PAA-CaP hybrid NPs might be greatly useful in pharmaceutical and other medical applications.

  6. Fluorescence and Judd-Ofelt analysis of rare earth complexes with maleic anhydride and acrylic acid

    WEN Shipeng; ZHANG Xiaoping; HU Shui; ZHANG Liqun; LIU Li

    2008-01-01

    Two kinds of Eu-complexes, Eu(TTA)2(Phen)(AA) and Eu(TTA)2(Phen)(MA) (HTFA=2-Thenoyltrifluoroacetone, Phen=1,10-phenanthroline, AA=acrylic acid, MA=Maleic anhydride), which combined the excellent fluorescence properties of Eu(TTA)2(Phen)(H2O) and the reactivity of acrylic acid and maleic anhydride with radicals, were synthesized. The two complexes were characterized by elemental analysis, infrared (IR) spectra, and X-ray photoelectron spectroscopy (XPS). Based on the data shown from the fluorescent spectra of the Eu-MA and Eu-AA complexes, the Ωλ (λ=2 and 4) experimental intensity parameters were calculated. The results demonstrated that the Ω2 intensity parameters for the two complexes were smaller than those for the Eu(TTA)2(Phen)(H2O) complex, indicating that a less symmetri-cal chemical environment existed in the complexes. It implied that the radiative efficiency of the 5D0 of these two complexes could be en-hanced by ligand of MA and AA, respectively. The luminescent lifetime of the Eu-AA (τ=7.26×10-4 s) or Eu-MA complex (τ=-8.12×10-4 s) was higher than that of the Eu(TTA)2(Phen)(H2O) complex, which was attributed to the substitution of the water molecule (H2O) in Eu(TTA)2(Phen)(H2O) by the MA or AA ligand.

  7. Corrosion Inhibitive Evaluation of an Environmentally Friendly Water-Base Acrylic Terpolymer on Mild Steel in Hydrochloric Acid Media

    Azghandi, Mojtaba Vakili; Davoodi, Ali; Farzi, Gholam Ali; Kosari, Ali

    2013-12-01

    The corrosion inhibitive performance of an environmentally friendly water-base acrylic terpolymer [methyl methacrylate/Butyl Acrylate/Acrylic acid (ATP)] on mild steel in 1 M HCl was investigated by alternating current and direct current electrochemical techniques and the quantum chemical method. An efficiency of more than 97 pct was obtained with 0.8 mmol/L ATP. The increase in inhibitor concentration and immersion time has a positive effect, while the temperature influence is negligible on the inhibitor efficiency. The present terpolymer obeys the Langmuir isotherm, and thermodynamic calculation reveals a chemisorption type on the surface. Density functional calculations showed that the lone pairs of electrons of oxygen in the structure of three monomers are suitable sites to adsorb onto the metal surface. Finally, in the presence of ATP, a decrease in surface roughness and corrosion attacks was demonstrated by atomic force microscopy and optical microscopy examinations, respectively.

  8. Thiomers: Influence of molecular mass and thiol group content of poly(acrylic acid) on efflux pump inhibition.

    Grabovac, Vjera; Laffleur, Flavia; Bernkop-Schnürch, Andreas

    2015-09-30

    The aim of the present study was to investigate the influence of molecular mass and thiol group content of poly(acrylic acid)-cysteine conjugates on the permeation of sulforhodamine 101 and penicillin G. acting as substrates for multidrug resistance-associated protein 2 efflux pump. Poly(acrylic acids) of 2 kDa, 100 kDa, 250 kDa, 450 kDa and 3000 kDa were conjugated with cysteine. The thiol group content of all these polymers was in the range from 343.3 ± 48.4 μmol/g to 450.3 ± 76.1 μmol/g. Transport studies were performed on rat small intestine mounted in Ussing-type chambers. Since 250 kDa poly(acrylic acid) showed the highest permeation enhancing effect, additionally thiolated 250 kDa polyacrylates displaying 157.2 μmol/g, 223.0 ± 18.1 and 355.9 μmol/g thiol groups were synthesized in order to investigate the influence of thiol group content on the permeation enhancement. The permeation of sulforhodamine was 3.93- and 3.85-fold improved using 250 kDa poly(acrylic acid)-cysteine conjugate exhibiting 355.9 ± 39.5 μmol/g and 223.0 ± 18.1 μmol/g thiol groups. Using the same conjugates the permeation of penicillin G was 1.70- and 1.59-fold improved, respectively. The study demonstrates that thiolated poly(acrylic acid) inhibits Mrp2 mediated transport and that the extent of inhibition depends on the molecular mass and degree of thiolation of the polymer. PMID:26238816

  9. Controlled release of insulin through hydrogels of (acrylic acid)/trimethylolpropane triacrylate

    Raymundi, Vanessa C.; Aguiar, Leandro G.; Souza, Esmar F.; Sato, Ana C.; Giudici, Reinaldo

    2015-12-01

    Hydrogels of poly(acrylic acid) crosslinked with trimethylolpropane triacrylate (TMPTA) were produced through solution polymerization. After these hydrogels were loaded with insulin solution, they evidenced swelling. Experiments of controlled release of insulin through the hydrogels were performed in acidic and basic media in order to evaluate the rates of release of this protein provided by the referred copolymer. Additionally, a mathematical description of the system based on differential mass balance was made and simulated in MATLAB. The model consists of a system of differential equations which was solved numerically. As expected, the values of swelling index at the equilibrium and the rates of insulin release were inversely proportional to the degree of crosslinking. The mathematical model provided reliable predictions of release profiles with fitted values of diffusivity of insulin through the hydrogels in the range of 6.0 × 10-7-1.3 × 10-6 cm2/s. The fitted and experimental values of partition coefficients of insulin between the hydrogel and the medium were lower for basic media, pointing out good affinity of insulin for these media in comparison to the acidic solutions.

  10. pH-Responsive Behavior of Poly(acrylic acid) Brushes of Varying Thickness

    Yadav, Vivek; Robertson, Megan; Conrad, Jacinta

    2015-03-01

    We have investigated the pH-dependent response of polyelectrolyte brushes of varying thickness. Our model system consists of poly(acrylic acid) brushes, which change from hydrophobic and neutral at low pH to hydrophilic and negatively charged at high pH, synthesized using a grafting-from approach at constant grafting density. As the polymer brush thickness increased, the brushes exhibited greater hysteresis in static water contact angle as a function of pH. We extracted the pKa of the polymer brushes from contact angle measurements. The relationship between the pKa and brush thickness depended on the order in which the brushes were exposed to solutions of varying pH: pKa decreased on increasing brush thickness when going from basic to acidic medium whereas pKa increased on increasing brush thickness when going from acidic to basic medium. We speculate that the origin of hysteresis can be explained by pH-dependent conformational changes in these polyelectrolyte brushes.

  11. Synthesis of poly acrylic acid modified silver nanoparticles and their antimicrobial activities

    Poly acrylic acid modified silver (Ag/PAA) nanoparticles (NPs) have been successfully synthesized in the aqueous solution by using tannic acid as a reductant. The structure, morphology and composition of Ag/PAA NPs were characterized by various techniques such as X-ray powder diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), ultraviolet–visible absorption spectroscopy (UV–vis) and thermogravimetry analysis (TGA). The results show that PAA/Ag NPs have a quasi-ball shape with an average diameter of 10 nm and exhibit well crystalline, and the reaction conditions have some effect on products morphology and size distribution. In addition, the as-synthesized Ag/PAA NPs antimicrobial activities against Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus) were evaluated by the methods of broth dilution, cup diffusion, optical density (OD600) and electron microscopy observation. The as-synthesized Ag/PAA NPs exhibit excellent antibacterial activity. The antimicrobial mechanism may be attributed to the damaging of bacterial cell membrane and causing leakage of cytoplasm. - Highlights: • Dispersed Ag/PAA NPs with small size were synthesized. • Ag/PAA NPs exhibited excellent antimicrobial properties. • Interaction mechanism between Ag/PAA NPs and bacteria was verified

  12. Synthesis of poly acrylic acid modified silver nanoparticles and their antimicrobial activities

    Ni, Zhihui [Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004 (China); Wang, Zhihua [Institute of Environmental and Analytical Sciences, College of Chemistry and Chemical Engineering, Henan University, Kaifeng 475004 (China); Sun, Lei, E-mail: sunlei@henu.edu.cn [Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004 (China); Li, Binjie [Key Laboratory of Cellular and Molecular Immunology, Henan University, Kaifeng 475004 (China); Zhao, Yanbao [Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004 (China)

    2014-08-01

    Poly acrylic acid modified silver (Ag/PAA) nanoparticles (NPs) have been successfully synthesized in the aqueous solution by using tannic acid as a reductant. The structure, morphology and composition of Ag/PAA NPs were characterized by various techniques such as X-ray powder diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), ultraviolet–visible absorption spectroscopy (UV–vis) and thermogravimetry analysis (TGA). The results show that PAA/Ag NPs have a quasi-ball shape with an average diameter of 10 nm and exhibit well crystalline, and the reaction conditions have some effect on products morphology and size distribution. In addition, the as-synthesized Ag/PAA NPs antimicrobial activities against Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus) were evaluated by the methods of broth dilution, cup diffusion, optical density (OD600) and electron microscopy observation. The as-synthesized Ag/PAA NPs exhibit excellent antibacterial activity. The antimicrobial mechanism may be attributed to the damaging of bacterial cell membrane and causing leakage of cytoplasm. - Highlights: • Dispersed Ag/PAA NPs with small size were synthesized. • Ag/PAA NPs exhibited excellent antimicrobial properties. • Interaction mechanism between Ag/PAA NPs and bacteria was verified.

  13. Synthesis of poly(acrylic acid-maleic acid)SiO2/Al2O3 as novel composite material for cesium removal from acidic solutions

    A novel composite material of SiO2-Al2O3 based on poly(acrylic acid-maleic acid) was synthesized by irradiated with 60Co γ-rays at a dose of 25 KGy. The composite material was characterized using FTIR, TGA and BET surface area. Adsorption of 134Cs from HNO3 was studied as a function of contact time, temperature and concentration of Cs. Sorption behavior of 134Cs in different concentration of HCl, HNO3, acetic acid, ascorbic acid, citric acid, NaCl and NaNO3 solutions has been investigated. It can be concluded that the P(AA-MA)/SiO2/Al2O3 is promising adsorbent for Cs removal from acidic liquid radioactive waste. (author)

  14. The effect of unsaturated fatty acid and triglyceride oil addition on the mechanical and antibacterial properties of acrylic bone cements.

    Persson, Cecilia; Robert, Elise; Carlsson, Elin; Robo, Céline; López, Alejandro; Godoy-Gallardo, Maria; Ginebra, Maria-Pau; Engqvist, Håkan

    2015-09-01

    Acrylic bone cements have an elastic modulus several times higher than the surrounding trabecular bone. This has been hypothesized to contribute to certain clinical complications. There are indications that the addition of specific fatty acids and triglyceride oils may reduce the elastic modulus of these types of cements. Some of these additives also appear to have inherent antibiotic properties, although this has never been evaluated in bone cements. In this study, several types of fatty acids and triglyceride oils were evaluated for use in acrylic bone cements. Their mechanical properties were evaluated under uniaxial compression testing and selected cements were then further characterized in terms of microstructure, handling and antibacterial properties using scanning electron microscopy, polymerization temperature measurements, agar diffusion tests and bactericidal activity assays of cement extracts. It was found that any of the evaluated fatty acids or triglyceride oils could be used to tailor the stiffness of acrylic bone cements, although at varying concentrations, which also depended on the type of commercial base cement used. In particular, the addition of very small amounts of linoleic acid (agar diffusion test as well as demonstrating 100% bactericidal activity against the same strain. PMID:25876889

  15. Preparation, characterization, and antibacterial activity studies of silver-loaded poly(styrene-co-acrylic acid) nanocomposites.

    Song, Cunfeng; Chang, Ying; Cheng, Ling; Xu, Yiting; Chen, Xiaoling; Zhang, Long; Zhong, Lina; Dai, Lizong

    2014-03-01

    A simple method for preparing a new type of stable antibacterial agent was presented. Monodisperse poly(styrene-co-acrylic acid) (PSA) nanospheres, serving as matrices, were synthesized via soap-free emulsion polymerization. Field-emission scanning electron microscopy micrographs indicated that PSA nanospheres have interesting surface microstructures and well-controlled particle size distributions. Silver-loaded poly(styrene-co-acrylic acid) (PSA/Ag-NPs) nanocomposites were prepared in situ through interfacial reduction of silver nitrate with sodium borohydride, and further characterized by transmission electron microscopy and X-ray diffraction. Their effects on antibacterial activity including inhibition zone, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and bactericidal kinetics were evaluated. In the tests, PSA/Ag-NPs nanocomposites showed excellent antibacterial activity against both gram-positive Staphylococcus aureus and gram-negative Escherichia coli. These nanocomposites are considered to have potential application in antibacterial coatings on biomedical devices to reduce nosocomial infection rates. PMID:24433897

  16. Synthesis of Hydrogel Based on Nata De Coco and Acrylic Acid as Co-Monomer Using Free Radical Polymerization Method

    Nata de Coco or known as bacterial cellulose is produced by Acetobacter xylinum where it is more stable than plant cellulose. Moreover, it also provides outstanding advantages to be developed as an environmental responsive hydrogels. In this study the bacterial cellulose-g-acrylic acid hydrogel was synthesized by using a free radical polymerization method. Ammonium persulfate (APS) was used to initiate the reaction, while N,N'-methylene bis acrylamide has been used as the crosslinking agent. In order to test the hydrogel respond, swelling tests were made at different pH. Furthermore, ATR-FTIR analysis was used to determine the interactions between bacterial cellulose and acrylic acid. Finally, the determination of glass transition (Tg) was made by using DSC. (author)

  17. Electron Beam Synthesis and Characterization of Acrylamide/Acrylic Acid Hydrogels Using Trimethylolpropane Trimethacrylate as Cross-Linker

    Gabriela Craciun

    2016-01-01

    Full Text Available The purpose of the paper is to present the synthesis and characterization of hydrogels prepared by free-radical copolymerization of acrylamide and acrylic acid in aqueous solutions using potassium persulfate as initiator and trimethylolpropane trimethacrylate as cross-linker, via the radiation technique. The samples were subjected to electron beam treatment in the dose range of 2 to 4 kGy and the influence of the absorbed dose and amount of cross-linker on the swelling properties, diffusion coefficient, and network parameters of hydrogels was investigated. A possible reaction mechanism for acrylamide/acrylic acid/trimethylolpropane trimethacrylate hydrogels was also suggested. The structure and morphology of hydrogels were characterized by Fourier Transform Infrared Spectroscopy and Scanning Electron Microscopy.

  18. The influence of poly(acrylic) acid number average molecular weight and concentration in solution on the compressive fracture strength and modulus of a glass-ionomer restorative.

    Dowling, Adam H

    2011-06-01

    The aim was to investigate the influence of number average molecular weight and concentration of the poly(acrylic) acid (PAA) liquid constituent of a GI restorative on the compressive fracture strength (σ) and modulus (E).

  19. Structural Parameters and Swelling Behavior of pH Sensitive Poly(acrylamide-co-acrylic acid) Hydrogels

    Thakur, A; Wanchoo, R. K.; Singh, P

    2011-01-01

    In the present work, hydrogels based on acrylamide (AAm) and acrylic acid (AAc), crosslinked with N,N’-methylenebisacrylamide (MBAAm) were prepared by free radical polymerization in solution. The effect of initial AAm/AAc mole ratio and nominal crosslinking ratio (moles of crosslinking agent/moles of polymer repeat unit) on the dynamic and equilibrium swelling behaviour of hydrogels was investigated. Hydrogels were characterized by the polymer volume fraction in the swollen state (ν2,s ), the...

  20. Poly(acrylic acid) interpolymer complexation: use of a fluorescence time resolved anisotropy as a poly(acrylamide) probe

    Swift, T.; Swanson, L; Rimmer, S.

    2014-01-01

    A low concentration poly(acrylamide) sensor has been developed which uses the segmental mobility of another polymer probe with a covalently attached fluorescent marker. Interpolymer complexation with poly(acrylic acid) leads to reduced segmental mobility which can be used to determine the concentration of polymer in solution. This technique could be useful in detecting the runoff of polymer dispersants and flocculants in fresh water supplies following water purification processes

  1. Rapid 3D Patterning of Poly(acrylic acid) Ionic Hydrogel for Miniature pH Sensors.

    Yin, Ming-Jie; Yao, Mian; Gao, Shaorui; Zhang, A Ping; Tam, Hwa-Yaw; Wai, Ping-Kong A

    2016-02-17

    Poly(acrylic acid) (PAA), as a highly ionic conductive hydrogel, can reversibly swell/deswell according to the surrounding pH conditions. An optical maskless -stereolithography technology is presented to rapidly 3D pattern PAA for device fabrication. A highly sensitive miniature pH sensor is demonstrated by in situ printing of periodic PAA micropads on a tapered optical microfiber. PMID:26643765

  2. Improvement in the behavior of bromelain coupled to pNIPAm polymers containing acrylamide or acrylic acid

    Rubab Mahmood

    2014-01-01

    Bromelain was coupled to N-isopropyl acrylamide (NIPAm)polymers, synthesized using NIPAm and various concentrations of acrylamide (Ac) or acrylic acid (AAc). Incorporation of Ac/AAcinto the polymer increased the LCST (lower critical solutiontemperature) in a concentration dependent manner but AAc wasmore effective in this regard; the LCST rose to 40°C when 6 percent AAc was used. Incorporation of Ac/AAc increased the coupling of enzyme to the polymer and the η (effectiveness factor) o...

  3. Obtention and characterization of acrylic acid-i-polyethylene organometallic copolymers with Mo, Fe, Co, Zn, and Ni

    In this study a graft acrylic acid (AA) in low density polyethylene (PEBD) copolymers were prepared, using as reaction initiator, gamma radiation at different doses. These copolymers were coordinated with molybdenum, cobalt, iron, zinc and nickel. the obtained polymeric materials were characterized by conventional analysis techniques. It was studied the measurement parameter variation of the positron annihilation when they inter activated with this type of materials and so obtaining information about microstructure of these polymers. (Author)

  4. Experimental Study and Numerical Solution of Poly Acrylic Acid Supported Magnetite Nanoparticles Transport in a One-Dimensional Porous Media

    M. Golzar; S. F. Saghravani; Azhdari Moghaddam, M.

    2014-01-01

    Recently, iron nanoparticles have attracted more attention for groundwater remediation due to its potential to reduce subsurface contaminants such as PCBs, chlorinated solvents, and heavy metals. The magnetic properties of iron nanoparticles cause to attach to each other and form bigger colloid particles of iron nanoparticles with more rapid sedimentation rate in aqueous environment. Using the surfactants such as poly acrylic acid (PAA) prevents iron nanoparticles from forming large flocs tha...

  5. Synthesis of poly(acrylic acid) nanogels by preparative pulse radiolysis

    Nanogels are sub-micron size, water-swellable crosslinked structures of hydrophilic polymers. In this work a radiation-based synthesis method that has been previously tested for neutral polymers is applied for production of nanogels of a synthetic polyelectrolyte--poly(acrylic acid) (PAA). In this technique dilute, deoxygenated PAA solution (pH 2) circulating in a closed loop is subjected to pulse irradiation with fast electrons. In each pulse many tens of radicals are instantaneously formed on every macromolecule. One of the major reaction paths of these radicals is intramolecular recombination leading to the formation of nanogels. It is demonstrated that radiation-induced reactions in our system show a typical feature of intramolecular crosslinking, i.e. a strong decrease in dimensions of a polymer coil without an accompanying decrease in molecular weight. In accordance with expectations based on earlier observations on non-polar polymers, intramolecular recombination of PAA-derived radicals proceeds according to non-classical kinetics. A model of non-homogeneous kinetics with time-dependent rate constant has been applied to describe this behaviour and the relationship between kinetic parameters and initial average number of radicals per chain is briefly discussed. The weight-average molecular weight of the products is influenced by side reactions, mainly degradation (chain breakage) and intermolecular crosslinking

  6. Poly(acrylic acid) coating induced 2-line ferrihydrite nanoparticle transport in saturated porous media

    Iron oxide and iron nanoparticles (NPs) have been used effectively for environmental remediation, but are limited in their applications by strong retention in groundwater-saturated porous media. For example, delivery of NPs to large groundwater reservoirs would require large numbers of injection wells. To address this problem, we have explored polymer coatings as a surface engineering strategy to enhance transport of oxide nanoparticles in porous media. We report here on our studies of 2-line ferrihydrite NPs and the influence of poly (acrylic acid) (PAA) polymer coatings on the colloidal stability and transport in natural sand-packed column tests simulating flow in groundwater-saturated porous media. Measurements were also made of zeta potential, hydrodynamic diameter, and polymer adsorption and desorption properties. The coated NPs have a diameter range of 30–500 nm. We found that NP transport was improved by PAA coating and that the transport properties could be tuned by adjusting the polymer concentration. Our results demonstrate that a high stability of oxide particles and improved transport can be achieved in groundwater-saturated porous media by introducing negatively charged polyelectrolytes and optimizing polymer concentrations

  7. Development of Graft Copolymer Flocculant Based on Acrylamide and Acrylic Acid for the dewatering of coal

    Most coal preparation processes were carried out in water medium. The water content of coal product has a negative impact on handling and specific energy value. The moisture content may be attributed to the proportion of fine coal, which presents the greatest dewatering problem. A novel polymeric flocculant has been developed by graft copolymerization of acrylamide (AAm) with acrylic acid (AAc) using gamma irradiation technique. The grafted copol621621ymer P(AAm/AAc) was characterized by Fourier-transform infrared spectroscopy (FTIR), and thermo-gravimetric analysis (TGA). The effects of reaction parameters, such as total absorbed dose, and monomer concentration on grafting yield were investigated. The flocculation performance of the graft copolymer P(AAm/AAc) was investigated in coal suspension. It was observed that the grafting ratio was one of the key factors for the flocculating effects. The copolymers with various grafting ratios showed different flocculating properties. It was found that as the grafting ratio increased, the flocculating effect also increased. The flocculation performance of the grafted copolymer was better than that of the commercial flocculant, poly-acrylamide (Magnafloc 1011).

  8. Poly(acrylic acid) coating induced 2-line ferrihydrite nanoparticle transport in saturated porous media

    Xiang, Aishuang [Princeton University, Chemical and Biological Engineering Department (United States); Yan, Weile [Texas Tech University, Civil and Environmental Engineering (United States); Koel, Bruce E., E-mail: bkoel@princeton.edu [Princeton University, Chemical and Biological Engineering Department (United States); Jaffe, Peter R., E-mail: jaffe@princeton.edu [Princeton University, Civil and Environmental Engineering Department (United States)

    2013-07-15

    Iron oxide and iron nanoparticles (NPs) have been used effectively for environmental remediation, but are limited in their applications by strong retention in groundwater-saturated porous media. For example, delivery of NPs to large groundwater reservoirs would require large numbers of injection wells. To address this problem, we have explored polymer coatings as a surface engineering strategy to enhance transport of oxide nanoparticles in porous media. We report here on our studies of 2-line ferrihydrite NPs and the influence of poly (acrylic acid) (PAA) polymer coatings on the colloidal stability and transport in natural sand-packed column tests simulating flow in groundwater-saturated porous media. Measurements were also made of zeta potential, hydrodynamic diameter, and polymer adsorption and desorption properties. The coated NPs have a diameter range of 30-500 nm. We found that NP transport was improved by PAA coating and that the transport properties could be tuned by adjusting the polymer concentration. Our results demonstrate that a high stability of oxide particles and improved transport can be achieved in groundwater-saturated porous media by introducing negatively charged polyelectrolytes and optimizing polymer concentrations.

  9. Carboxymethyl starch cross-linked by electron beam radiation in presence of acrylic acid sensitizer

    Carboxymethyl starch (CMS) can be cross-linked by electron beam radiation to form a biocompatible and environment-friendly hydrogel at a high absorbed dose and a condensed CMS concentration. Acrylic acid (AAc) can be used as a sensitizer in order to reduce the absorbed doses to an acceptable certain level. At an absorbed dose of 3-4 kGy, the gel content of crosslinked CMS can be obtained about 50% with 5% (w/w) AAc concentration used. The compressive strength of CMS samples increased with increasing their cross-linked densities due to raising absorbed doses. The swelling ratio of cross-linked CMS was also attainable at a maximum of 50 times in the distilled water. The enzymatic degradation of cross-linked CMS was carried out in acetate buffer pH 4.6 with 0.1% α-amylase enzymatic solution incubated at 40℃ for 6 h. The crosslinked CMS samples were degraded slower than uncrosslinked CMS ones. The results indicated that the highly cross-linked CMS was almost fully degradable when the enzymatic hydrolysis was performed during 6 h. The FT IR spectra of cross-linked CMS in the presence of AAc were examined to observe the carboxyl group of AAc in the structure of cross-linked CMS. The hydrophilic of cross-linked CMS surface was determined by a contact-angle analysis. (authors)

  10. Cellulose nanocrystal-filled poly(acrylic acid) nanocomposite fibrous membranes

    Lu, Ping; Hsieh, You-Lo

    2009-10-01

    Nanocomposite fibrous membranes have been fabricated by electrospinning cellulose nanocrystal (CNC)-loaded poly(acrylic acid) (PAA) ethanol mixtures. Incorporating CNC in PAA significantly reduced fiber diameters and improved fiber uniformity. The average diameters of the as-spun nanocomposite fibers were significantly reduced from 349 nm to 162 nm, 141 nm, 90 nm and 69 nm at 5%, 10%, 15% and 20% CNC loading (by weight of a constant 4% PAA solution), respectively. CNC was well dispersed in the fibers as isolated rods oriented along the fiber axis and as spheres in the PAA matrix. The Young modulus and stress of the PAA/CNC nanocomposite fibers were significantly improved with increasing CNC loadings by up to 35-fold and 16-fold, respectively. Heat-induced esterification between the CNC surface hydroxyls and PAA carboxyl groups produced covalent crosslinks at the CNC-PAA interfaces, rendering the nanocomposite fibrous membranes insoluble in water, more thermally stable and far more superior in tensile strength. With 20% CNC, the crosslinked nanocomposite fibrous membrane exhibited a very impressive 77-fold increase in modulus and 58-fold increase in stress.

  11. Cellulose nanocrystal-filled poly(acrylic acid) nanocomposite fibrous membranes

    Nanocomposite fibrous membranes have been fabricated by electrospinning cellulose nanocrystal (CNC)-loaded poly(acrylic acid) (PAA) ethanol mixtures. Incorporating CNC in PAA significantly reduced fiber diameters and improved fiber uniformity. The average diameters of the as-spun nanocomposite fibers were significantly reduced from 349 nm to 162 nm, 141 nm, 90 nm and 69 nm at 5%, 10%, 15% and 20% CNC loading (by weight of a constant 4% PAA solution), respectively. CNC was well dispersed in the fibers as isolated rods oriented along the fiber axis and as spheres in the PAA matrix. The Young modulus and stress of the PAA/CNC nanocomposite fibers were significantly improved with increasing CNC loadings by up to 35-fold and 16-fold, respectively. Heat-induced esterification between the CNC surface hydroxyls and PAA carboxyl groups produced covalent crosslinks at the CNC-PAA interfaces, rendering the nanocomposite fibrous membranes insoluble in water, more thermally stable and far more superior in tensile strength. With 20% CNC, the crosslinked nanocomposite fibrous membrane exhibited a very impressive 77-fold increase in modulus and 58-fold increase in stress.

  12. Synthesis and characterization of polycaprolactone/acrylic acid (PCL/AA) hydrogel for controlled drug delivery

    Nazar Mohammad Ranjha; Jahanzeb Mudassir; Sajid Majeed

    2011-12-01

    In the present work biodegradable pH-sensitive polycaprolactone/acrylic acid (PCL/AA) hydrogels have been developed using ethylene glycol dimethacrylate (EGDMA) as a cross-linker and benzoyl peroxide as initiator. For these prepared hydrogels swelling studies, sol–gel fraction analysis and porosity measurements were performed. Results show that swelling of the hydrogels decreases on increasing the concentration of PCL and EGDMA, however swelling of hydrogels increases on increasing the concentration of AA. Results of sol–gel fraction analysis show that gel fraction increases on increasing concentration of monomer AA, polymer PCL as well as cross-linker EGDMA. As far as porosity is concerned, it increases on increasing the concentration of AA and PCL while porosity decreases on increasing the concentration of EGDMA. Hydrogels were characterized by measuring diffusion coefficient () and equilibrium water content (EWC). Network formation, morphology and crystallinity of PCL/AA hydrogels were investigated using FTIR, SEM and XRD, respectively. Tramadol hydrochloride was loaded as model drug and its release pattern was analysed using various kinetic models like zero order, first order, Higuchi and Peppas. Results indicated that most of the samples followed non-Fickian release mechanism.

  13. Studies on surface graft polymerization of acrylic acid onto PTFE film by remote argon plasma initiation

    The graft polymerization of acrylic acid (AAc) was carried out onto poly(tetrafluoroethylene) (PTFE) films that had been pretreated with remote argon plasma and subsequently exposed to oxygen to create peroxides. Peroxides are known to be the species responsible for initiating the graft polymerization when PTFE reacts with AAc. We chose different parameters of remote plasma treatment to get the optimum condition for introducing maximum peroxides (2.87 x 10-11 mol/cm2) on the surface. The influence of grafted reaction conditions on the grafting degree was investigated. The maximum grafting degree was 25.2 μg/cm2. The surface microstructures and compositions of the AAc grafted PTFE film were characterized with the water contact angle meter, Fourier-transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS). Contact angle measurements revealed that the water contact angle decreased from 108o to 41o and the surface free energy increased from 22.1 x 10-5 to 62.1 x 10-5 N cm-1 by the grafting of the AAc chains. The hydrophilicity of the PTFE film surface was greatly enhanced. The time-dependent activity of the grafted surface was better than that of the plasma treated film

  14. Thermal Properties of Poly(allylamine hydrochloride)/Poly(acrylic acid) Layer-by-Layer Assemblies

    Lutkenhaus, Jodie; Shao, Lin

    2010-03-01

    Layer-by-layer (LbL) assemblies are promising for global energy and health applications, but their materials properties are not well understood. LbL assemblies are created from the alternate adsorption of oppositely charged species from solution to a substrate. Particularly, little is known about the thermal properties of LbL assemblies because the supporting substrate impedes characterization. It is not initially clear if electrostatic LbL assemblies possess a glass transition temperature, if they are rubbery or glassy, or if their heat capacity is comparable to their homopolymer constituents. Here, we isolate large areas of LbL assemblies from a low-energy substrate, which facilitates thermal characterization via modulated differential scanning calorimetry (MDSC) and thermal gravimetric analysis (TGA). LbL assemblies of poly(acrylic acid) (PAA) and poly(allylamine hydrochloride) (PAH) were deposited onto hydrophobic substrates, and subsequently isolated. Results highlight that PAH/PAA LbL films are glassy, and have low mobility because of the high density of ion pair crosslinks. The techniques presented here are general, and can be applied to any LbL film.

  15. Radiation grafting of ionically crosslinked alginate/chitosan beads with acrylic acid for lead sorption

    Radiation-induced grafting of acrylic acid onto alginate/chitosan beads was performed in solution at a dose rate of 20.6 Gy/min of Co-60 gamma rays. The effect of absorbed dose on grafting yield was investigated. The characterization of the grafted and un-grafted beads was performed by FTIR spectroscopy and the swelling measurements at different pHs was studied. It is found that as the pH value increases the swelling degree increases up to pH 6 but with further increase in pH value the swelling decreases. Also, it is noticed that the grafting yield increased with increase the irradiation dose. Both un-grafted and grafted alginate/chitosan beads were examined as sorbents for the removal of Pb ions from aqueous solutions. The sorption behavior of the sorbents was examined through pH, and equilibrium measurements. Grafted alginate/chitosan beads presented higher sorption capacity for Pb ions than un-grafted beads. (author)

  16. Synthesis, structure and phase transition property of acrylic acid grafted paraffin

    Zhao, Xiaowen; Liu, Pengfei; Ye, Lin

    2014-05-01

    Polar monomer acrylic acid (AA) was used to modify paraffin in order to improve the latent heat of paraffin as phase change materials. The composition and sequence structure of the grafted products were characterized by FTIR, 13C NMR, 1H NMR and GPC analysis, and the thermal properties of paraffin-g-AA were investigated. It was found that AA was confirmed to be grafted onto the molecular chain of paraffin successfully. The mechanism of free radical grafting of AA may be only monomeric grafts. At low grafting ratio, the structure B can be mainly formed as a result of the radical coupling termination; while at the high grafting ratio, structure A was the primary structure as a result of the radical chain growth process. The number-average molecular weight of the grafted samples increased at first but leveled off with increasing grafting ratio, while the weight-average molecular weight increased gradually. The latent heat capacity of the grafted paraffin can be improved obviously at low grafting ratio due to the formation of structure B.

  17. Study on Radiated Polymerization of Acrylic Acid on Montmorillonite and Bentonite Used as Bioactivity Carriers

    The radiated polymerization of acrylic acid (AAc) on bentonite (BT) and montmorillonite (MMT) having structured silicate layers to produce hybrid materials were investigated. AAc concentrations of 10 and 40 % w/w were used to polymerize with MMT and BT at the absorbed doses of 3.6 and 6.4 kGy, respectively. The formed PAAc concentration of MMT-PAAc was 68 % and 40 % for BT-PAAc. The results of X-ray diffraction patterns were indicated that, the basal distances (d001) of MMT and BT after polymerization were ≈ 15 Å compared with BT was 12.17 Å and MMT did not appear the d001 peak. The cellulase immobilized yields of MMT-AAc and BT-AAc were determined by Lowry method with values were of 40.6 % and 68.3 %, respectively. The cellulase activity of the immobilization samples were checked by diffusion the sample solutions on agar after that measure of diameter of CMC hydrolysis circles. The results indicated that, the immobilized cellulase samples still maintain enzymatic activity after three times reuse. (author)

  18. Synthesis and characterization of zinc chloride containing poly(acrylic acid) hydrogel by gamma irradiation

    In this study, the characterization of zinc chloride incorporated into a poly(acrylic acid) (PAAc) hydrogel prepared by gamma-ray irradiation was investigated. Zinc chloride powder with different concentrations was dissolved in the PAAc solution, and it was crosslinked with gamma-ray irradiation. The effects of various parameters such as zinc ion concentration and irradiation doses on characteristics of the hydrogel formed were investigated in detail for obtaining an antibacterial wound dressing. In addition, the gel content, pH-sensitive (pH 4 or 7) swelling ratio, and UV–vis absorption spectra of the zinc particles in the hydrogels were characterized. Moreover, antibacterial properties of these new materials against Staphylococcus aureus and Escherichia coli strains were observed on solid growth media. The antibacterial tests indicated that the zinc chloride containing PAAc hydrogels have good antibacterial activity. - Highlights: • The characterization of zinc chloride containing PAA hydrogel was investigated. • The gel content increased with an increase in absorbed dose up to 75 kGy. • Finally, the zinc chloride based hydrogels have an antibacterial activity

  19. Preparation and properties of poly(acrylic acid) oligomer stabilized superparamagnetic ferrofluid.

    Lin, Chia-Lung; Lee, Chia-Fen; Chiu, Wen-Yen

    2005-11-15

    Ferrofluids, which are stable dispersions of magnetic particles, behave as liquids that have strong magnetic properties. Nanoparticles of magnetite with a mean diameter of 10-15 nm, which are in the range of superparamagnetism, are usually prepared by the traditional method of co-precipitation from ferrous and ferric electrolyte solution. When diluted, the ferrofluid dispersions are not stable if anionic or cationic surfactants are used as the stabilizer. This work presents an efficient way to prepare a stable aqueous nanomagnetite dispersion. A stable ferrofluid containing Fe3O4 nanoparticles was synthesized via co-precipitation in the presence of poly(acrylic acid) oligomer. The mechanism, microstructure, and properties of the ferrofluid were investigated. The results indicate that the PAA oligomers promoted the nucleation and inhibited the growth of the magnetic iron oxide, and the average diameter of each individual Fe3O4 particle was smaller than 10 nm. In addition, the PAA oligomers provided both electrostatic and steric repulsion against particle aggregation, and the stability of dispersions could be controlled by adjusting the pH value of solution. A small amount of Fe2O3 was found in the nanoparticles but the superparamagnetic behavior of the nanoparticles was not affected. PMID:16009367

  20. Potassium fulvate as co-interpenetrating agent during graft polymerization of acrylic acid from cellulose.

    Ghazy, Mohamed B M; El-Hai, Farag Abd; Mohamed, Magdy F; Essawy, Hisham A

    2016-10-01

    Grafting polymerization of acrylic acid onto cellulose in presence of potassium fulvate (KF) as a co-interpenetrating agent results enhanced water sorption compared to materials prepared similarly in its absence. The insertion of potassium fulvate (KF) did not affect the grafting process and is thought to proceed in parallel to the graft polymerization via intensive polycondensation reactions of its function groups (-COOH and OH) with COOH of the monomer and OH groups of cellulose. The combination of graft copolymerization and polycondensation reactions is assumed to produce interpenetrating network structure. Fourier transform infrared (FTIR) confirmed successful incorporation within the network structure which is an evidence for formation of interpenetrating network. The obtained structures showed homogeneous uniform surface as revealed by scanning electron microscopy (SEM). The obtained superabsorbent possessed high water absorbency 422 and 48.8g/g in distilled water and saline (0.9wt.% NaCl solution), respectively, and enhanced water retention even at elevated temperatures as revealed by thermogravimetric analysis (TGA). This could be explained by the high content of hydrophilic groups. The new superabsorbents proved to be efficient devices for controlled release of fertilizers which expands their use in agricultural applications. PMID:27370745

  1. Antimicrobial activity of poly(vinyl alcohol)-poly(acrylic acid) electrospun nanofibers.

    Santiago-Morales, Javier; Amariei, Georgiana; Letón, Pedro; Rosal, Roberto

    2016-10-01

    Electrospun nanofibers were prepared from blends of poly(acrylic acid) (PAA) and poly(vinyl alcohol) (PVA). The fibers were stabilized by heat curing at 140°C via anhydride and ketone formation and crosslinking esterification. The antimicrobial effect was assessed using strains of Escherichia coli and Staphylococcus aureus by tracking their capacity to form colonies and their metabolic impairment upon contact with PAA/PVA membranes. Membranes containing >35wt.% PAA displayed significant antibacterial activity, which was particularly high for the gram-positive S. aureus. All membranes were negatively charged, with surface ζ-potential in the (-34.5)-(-45.6)mV range, but the electrostatic interaction with the negatively charged cells was not the reason for the antimicrobial effect. Neither pH reduction nor the passing of non-crosslinked polymers to the solution affected microbial growth. The antibacterial activity was attributed to the chelation of the divalent cations stabilizing the outer cell membrane. The effect on gram-positive bacteria was attributed to the destabilization of the peptidoglycan layer. The sequestration of divalent cations was demonstrated with experiments in which calcium and a chelating agent were added to the cultures in contact with membranes. The damage to bacterial cells was tracked by measuring their surface charge and the evolution of intracellular calcium during the early stages after contact with PAA/PVA membranes. PMID:27318959

  2. AFM Analysis of Copolymer From Konjac With Acrylic Acid by γ Irradiation

    The water absorption property and atomic force microscopy (AFM) analysis were studied to discover the relativity of water absorption and construction of original konjac powder, grafted copolymer and regenerator. The results show that the water absorption, speed and reserving percent of the grafted copolymer are affected by the size, the liquid ion concentration, the ambient temperature and water reserving time of the gel. At room temperature, the largest water absorption, water absorption speed and water reserving percent of grafted copolymer are 887 times, 64.7 g·g-1·min-1 and 92% in distilled water and 273 times, 27.6 g·g-1·min-1 and 84% in tap water respectively. The AFM images of grafted copolymer indicate that konjac grafts acrylic acid and then hydrophilic structure comes into being. During the course of regeneration the three dimensional structure of the copolymer was changed to more regularly. So the water absorption of copolymer is higher than that of konjac, and the water absorption of regenerator is 360 times, higher than that of copolymer. (authors)

  3. Synthesis and characterization of acrylamide-acrylic acid hydrogels and adsorption of some textile dyes

    Acrylamide (AAm)-acrylic acid (AAc) hydrogels have been prepared at AAm initial compositions of 15%, 20% and 30%. AAm-AAc monomer mixtures have been irradiated in a 60Co-γ source at different doses and percent conversions have been determined gravimetrically. 100% conversion of monomers into hydrogels was achieved at 8 kGy dose. These hydrogels were swollen in distilled water at pH 3.03, 4.18, 4.68, 5.05, 5.30, 6.0, 7.0, 8.0. The results of swelling tests at pH 8.0 indicated that poly(AAm-AAc) hydrogels prepared from solution containing 15% (mol%) AAm showed maximum % swelling as 3000%. Poly(AAm-AAc) hydrogels have been considered for the removal of some textile dyes from aqueous solutions. Among the two common textile dyes tested, Janus Green B (JGB) has showed the highest adsorption capacity while Congo Red (CR) was not adsorbed by these hydrogels. Adsorption isotherms were constructed for JGB and poly(AAm/AAc) gel systems. It is concluded that cross-linked poly(AAm/AAc) hydrogels can be successfully used in the purification of waste water containing certain textile dyes

  4. Mechanically stable thermally crosslinked poly(acrylic acid)/reduced graphene oxide aerogels.

    Ha, Heonjoo; Shanmuganathan, Kadhiravan; Ellison, Christopher J

    2015-03-25

    Graphene oxide (GO) aerogels, high porosity (>99%) low density (∼3-10 mg cm(-3)) porous materials with GO pore walls, are particularly attractive due to their lightweight, high surface area, and potential use in environmental remediation, superhydrophobic and superoleophilic materials, energy storage, etc. However, pure GO aerogels are generally weak and delicate which complicates their handling and potentially limits their commercial implementation. The focus of this work was to synthesize highly elastic, mechanically stable aerogels that are robust and easy to handle without substantially sacrificing their high porosity or low density. To overcome this challenge, a small amount of readily available and thermally cross-linkable poly(acrylic acid) (PAA) was intermixed with GO to enhance the mechanical integrity of the aerogel without disrupting other desirable characteristic properties. This method is a simple straightforward procedure that does not include multistep or complicated chemical reactions, and it produces aerogels with mass densities of about 4-6 mg cm(-3) and >99.6% porosity that can reversibly support up to 10,000 times their weight with full recovery of their original volume. Finally, pressure sensing capabilities were demonstrated and their oil absorption capacities were measured to be around 120 g oil per g aerogel(-1) which highlights their potential use in practical applications. PMID:25714662

  5. Removal of some basic dyes by poly (Vinyl Alcohol/ acrylic acid)Hydrogel

    A study has made on the preparation and properties of poly (vinyl alcohol/ acrylic acid) hydrogel for the purpose of removal of cationic dyes from aqueous solutions. The effect of dose and monomer concentration on the uptake property of the hydrogel toward dye was studied. The uptake of basic methylene blue-9 dye with PVA/AAc was studied by the batch adsorption technique. The effect of pH on the dye uptake was demonstrated to find out that the suitable pH for maximum uptake occurred at pH 5. It was observed that as the concentration of dye is increased the dye uptake decreased. Furthermore, the uptake of dye by hydrogels increased as the temperature was elevated. The recovery of dye adsorbed is possible by treating the hydrogel with 5% HCl. The results obtained suggested this hydrogel possessed good removal properties towards basic methylene blue-9 dye, and this suggests that such hydrogels could be acceptable for practical uses

  6. Removal of cationic dyes by poly(acrylamide-co-acrylic acid) hydrogels in aqueous solutions

    Poly(acrylamide-co-acrylic acid (poly(AAm-co-AAc)) hydrogels prepared by irradiating with γ-radiation were used in experiments on swelling, diffusion, and uptake of some cationic dyes such as Safranine-O (SO) and Magenta (M). Poly(AAm-co-AAc) hydrogels irradiated at 8.0 kGy have been used for swelling and diffusion studies in water and cationic dye solutions. The maximum swellings in water, and SO, and M solutions observed are 2700%, 3500%, and 4000%, respectively. Diffusions of water and cationic dyes within hydrogels have been found to be non-Fickian in character. Adsorption of the cationic dyes onto poly(AAm-co-AAc) hydrogels is studied by the batch adsorption technique. The adsorption type was found Langmuir type in the Giles classification system. The moles of adsorbed dye for SO and M per repeating unit in hydrogel (binding ratio, r) have been calculated as 3834x10-6 and 1323x10-6, respectively. These results show that poly(AAm-co-AAc) hydrogels can be used as adsorbent for water pollutants such as cationic dyes

  7. Syntheses and Crystal Structures of Two Complexes with 3-(3-Pyridyl)acrylic Acid

    2005-01-01

    The reaction of 3-(3-pyridyl)acrylic acid (H(3-PYA)) with Co(NO3)2·6H2O or Complex 1 crystallizes in monoclinic, space group C2/c with a = 9.9473(12), b = 13.7227(16), c =14.7376(18) (A), β = 99.043(2)°, V = 1986.7(4) (A)3, Z = 4, Dc = 1.549 g/cm3, μ = 0.921 mm 1, F(000)= 964, R = 0.0786 and wR = 0.1443. Six types of hydrogen bonds and π-π packing interactions molecular architecture. Complex 2 crystallizes in monoclinic, space group P21/n with a =11.3630(16), b = 7.0346(10), c = 12.1365(18) (A), β = 112.545(3)°, V = 896.0(2) (A)3, Z = 2, Dc =1.997 g/cm3,μ = 0.785 mm-1, F(000) = 438, R = 0.0787 and wR = 0.1550. The discrete entity Mn(Ⅱ)(3-PYD)2(H2O)4 is extended into a 3-D supramolecular architecture by four kinds of hydrogen bonds.

  8. Poly(acrylic acid) brushes pattern as a 3D functional biosensor surface for microchips

    Wang, Yan-Mei; Cui, Yi; Cheng, Zhi-Qiang; Song, Lu-Sheng; Wang, Zhi-You; Han, Bao-Hang; Zhu, Jin-Song

    2013-02-01

    Poly(acrylic acid) (PAA) brushes, a novel three dimensional (3D) precursor layer of biosensor or protein microarrays, possess high protein loading level and low non-specific protein adsorption. In this article, we describe a simple and convenient way to fabricate 3D PAA brushes pattern by microcontact printing (μCP) and characterize it with FT-IR and optical microscopy. The carboxyl groups of PAA brushes can be applied to covalently immobilize protein for immunoassay. Thriving 3D space made by patterning PAA brushes thin film is available to enhance protein immobilization, which is confirmed by measuring model protein interaction between human immunoglobulin G (H-IgG) and goat anti-H-IgG (G-H-IgG) with fluorescence microscopy and surface plasmon resonance imaging (SPRi). As expected, the SPRi signals of H-IgG coating on 3D PAA brushes pattern and further measuring specific binding with G-H-IgG are all larger than that of 3D PAA brushes without pattern and 2D bare gold surface. We further revealed that this surface can be used for high-throughput screening and clinical diagnosis by label-free assaying of Hepatitis-B-Virus surface antibody (HBsAb) with Hepatitis-B-Virus surface antigen (HBsAg) concentration array chip. The linearity range for HBsAb assay is wider than that of conventional ELISA method.

  9. Graft copolymerization of N-maleoyl-N-phthaloyl-chitosan (MAPHCS) and acrylic acid via γ-ray irradiation

    Chitosan is a well-known abundant natural polymer with good biodegradability, biocompatibility and bioactivity. But its insolubility in common organic solvents of chitosan have hindered its utilization and basic research. N-maleoyl-N-phthaloyl-chitosan (MAPHCS), soluble in DMF or DMSO, was synthesized and characterized by Fourier transform infrared spectra analysis (FT-IR) and 1H-NMR. The graft copolymerization of acrylic acid onto chitosan was carried out with N-maleoyl-N-phthaloyl-chitosan as intermediate in homogeneous system and initiated by γ-irradiation. The double bond of MAPHCS may be the grafting site because the grafting field was much higher than that of the graft copolymerization of acrylic acid and phthaloylchitosan via γ-ray irradiation. The chemical structure of the graft copolymer was characterized by FT-IR and 1H-NMR. As indicated in FTIR spectra, the evidence of the stronger absorbance at 2800-3000 cm-1 for C-H and at 1720 cm-1 for carboxyl group implied significantly the successful introduction of the poly (acrylic acid) on the chitosan chain. Differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) were also used to characterize the copolymer. Effects of synthesis variables on the graft copolymerization were studied in light of the grafting percentage. The grafting percentage increased with the dose at lower doses, and then decreased. The maximum grafting percentage was up to 132%. (authors)

  10. Acetic and Acrylic Acid Molecular Imprinted Model Silicone Hydrogel Materials for Ciprofloxacin-HCl Delivery

    Lyndon Jones

    2012-01-01

    Full Text Available Contact lenses, as an alternative drug delivery vehicle for the eye compared to eye drops, are desirable due to potential advantages in dosing regimen, bioavailability and patient tolerance/compliance. The challenge has been to engineer and develop these materials to sustain drug delivery to the eye for a long period of time. In this study, model silicone hydrogel materials were created using a molecular imprinting strategy to deliver the antibiotic ciprofloxacin. Acetic and acrylic acid were used as the functional monomers, to interact with the ciprofloxacin template to efficiently create recognition cavities within the final polymerized material. Synthesized materials were loaded with 9.06 mM, 0.10 mM and 0.025 mM solutions of ciprofloxacin, and the release of ciprofloxacin into an artificial tear solution was monitored over time. The materials were shown to release for periods varying from 3 to 14 days, dependent on the loading solution, functional monomer concentration and functional monomer:template ratio, with materials with greater monomer:template ratio (8:1 and 16:1 imprinted tending to release for longer periods of time. Materials with a lower monomer:template ratio (4:1 imprinted tended to release comparatively greater amounts of ciprofloxacin into solution, but the release was somewhat shorter. The total amount of drug released from the imprinted materials was sufficient to reach levels relevant to inhibit the growth of common ocular isolates of bacteria. This work is one of the first to demonstrate the feasibility of molecular imprinting in model silicone hydrogel-type materials.

  11. Radiation grafting of acrylic acid onto partially deacetylated chitin for metal ion adsorbent

    Radiation processing technology is proved to be a useful tool for modification of polymer material including grafting of monomer onto polymer. In this study, partially deacetylated chitin (PD-chitin) was prepared by soaking chitin in NaOH solution with various concentrations from 10% to 50% (w/w) at room temperature for four days. The degree of deacetylation (DD%) of chitin samples was measured by IR spectroscopy method. Radiation grafting of acrylic acid (AAc) onto PD-chitin was carried out by immerging PD-chitin in AAc solution (5-20%v/v) for swelling two days. The swelled PD-chitin sample was filtered and irradiated with Co-60 radiation at dose of 4.8 kGy for grafting. The resulting product, so called PD-chitin-g-PAA was changed to sodium form, PD-chitin-g-PANa by treating with NaOH 1 N and used as metal ion adsorbent. The adsorption capacities of studied chitin samples for metal ion typically for Cu2+ was determined using atomic absorption spectrophotometer. The results showed that the adsorption capacities for Cu2+ were as the following order: chitin L = 15.5 and 19.4 (mg/g); b = 0.02 and 0.04 (L/mg) for PD-chitin and PD-chitin-g-PANa, respectively. The obtained product, PD-chitin-g-PANa can be produced on large scale with competitive cost and used as metal ion adsorbent for water purification as well as for other purposes such as for sorption of dyes and for immobilization of bioactive substances

  12. Radiation grafting of acrylic acid onto partially deacetylated chitin for metal ion adsorbent

    Nguyen Quoc Hien [Research and Development Center for Radiation Technology, Vietnam Atomic Energy Commission, Truong tre Str., Linh xuan, Thu duc, Ho Chi Minh City (Viet Nam)]. E-mail: hiennq@hcm.vnn.vn; Dang Van Phu [Research and Development Center for Radiation Technology, Vietnam Atomic Energy Commission, Truong tre Str., Linh xuan, Thu duc, Ho Chi Minh City (Viet Nam); Nguyen Ngoc Duy [College of Natural Sciences, National University Ho Chi Minh City, 227 Nguyen Van Cu, Ho Chi Minh City (Viet Nam); Ha Thuc Huy [College of Natural Sciences, National University Ho Chi Minh City, 227 Nguyen Van Cu, Ho Chi Minh City (Viet Nam)

    2005-07-01

    Radiation processing technology is proved to be a useful tool for modification of polymer material including grafting of monomer onto polymer. In this study, partially deacetylated chitin (PD-chitin) was prepared by soaking chitin in NaOH solution with various concentrations from 10% to 50% (w/w) at room temperature for four days. The degree of deacetylation (DD%) of chitin samples was measured by IR spectroscopy method. Radiation grafting of acrylic acid (AAc) onto PD-chitin was carried out by immerging PD-chitin in AAc solution (5-20%v/v) for swelling two days. The swelled PD-chitin sample was filtered and irradiated with Co-60 radiation at dose of 4.8 kGy for grafting. The resulting product, so called PD-chitin-g-PAA was changed to sodium form, PD-chitin-g-PANa by treating with NaOH 1 N and used as metal ion adsorbent. The adsorption capacities of studied chitin samples for metal ion typically for Cu{sup 2+} was determined using atomic absorption spectrophotometer. The results showed that the adsorption capacities for Cu{sup 2+} were as the following order: chitin < PD-chitin < PD-chitin-g-PANa < chitosan (DD76%). In addition, equilibrium isotherms were well fitted by Langmuir equation with the constants K {sub L} = 15.5 and 19.4 (mg/g); b = 0.02 and 0.04 (L/mg) for PD-chitin and PD-chitin-g-PANa, respectively. The obtained product, PD-chitin-g-PANa can be produced on large scale with competitive cost and used as metal ion adsorbent for water purification as well as for other purposes such as for sorption of dyes and for immobilization of bioactive substances.

  13. Hydrophobically Modified Polyelectrolytes: V. Interaction of Fluorocarbon Modified Poly (acrylic acid) with Various Added Surfactants

    ZHOU,Hui(周晖); SONG,Guo-Qaiang(宋国强); GUO,Jin-Feng(郭金峰); ZHANG,Yun-xiang (章云祥); DIEING,Reinhold; MA,Lian(马莲); HAEUSSLING,Lukas

    2001-01-01

    The interactions between fiuorocarbon-medified pol(sodium acrylate) and various kinds of added surfactant have been studied by means of viscometric measurement. Association behavior was found in both hydrogenated and fluorinated anionic, nonionic and cationic surfactants. Among them, the interactions between fluorocarbon-modified poly ( sodium acrylate) and cationic surfactants are the strongest, owing to the cooperation of both electrostatic attractions and hydrophobic associations. The anionic surfactants have the weakest effects on the solution properties because of the existence of unfavorable electrostatic repulsion. The hydrophobic interactions between copolymers and fluorinated surfactants are much stronger than those between copolymers and hydrogenated surfactants.

  14. SYNTHESIS AND IN VITRO CHARACTERIZATION OF HYDROXYPROPYL METHYLCELLULOSE-GRAFT-POLY (ACRYLIC ACID/2-ACRYLAMIDO-2-METHYL-1-PROPANESULFONIC ACID) POLYMERIC NETWORK FOR CONTROLLED RELEASE OF CAPTOPRIL.

    Furqan Muhammad, Iqbal; Mahmood, Ahmad; Aysha, Rashid

    2016-01-01

    A super-absorbent hydrogel was developed by crosslinking of 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) and acrylic acid with hydroxypropyl methylcellulose (HPMC) for controlled release drug delivery of captopril, a well known antihypertensive drug. Acrylic acid and AMPS were polymerized and crosslinked with HPMC by free radical polymerization, a widely used chemical crosslinking method. N,N'-methylenebisacrylamide (MBA) and potassium persulfate (KPS) were added as cross-linker and initiator, respectively. The hydrogel formulation was loaded with captopril (as model drug). The concentration of captopril was monitored at 205 nm using UV spectrophotometer. Equilibrium swelling ratio was determined at pH 2, 4.5 and 7.4 to evaluate the pH responsiveness of the formed hydrogel. The super-absorbent hydrogels were evaluated by FTIR, SEM, XRD, and thermal analysis (DSC and TGA). The formation of new copolymeric network was determined by FTIR, XRD, TGA and DSC analysis. The hydrogel formulations with acrylic acid and AMPS ratio of 4: 1 and lower amounts of crosslinker had shown maximum swelling. Moreover, higher release rate of captopril was observed at pH 7.4 than at pH 2, because of more swelling capacity of copolymer with increasing pH of the aqueous medium. The present research work confirms the development of a stable hydrogel comprising of HPMC with acrylic acid and AMPS. The prepared hydrogels exhibited pH sensitive behav-ior. This superabsorbent composite prepared could be a successful drug carrier for treating hypertension. PMID:27008813

  15. SYNTHESIS OF POLY(DIVINYLBENZENE-co-ACRYLIC ACID) HOLLOW MICROSPHERES WITH GOLD NANOPARTICLES ON THE INTERIOR SURFACE

    Wei Liu; Xin-lin Yang; Xu-gang He

    2009-01-01

    Poly(divinylbenzene-co-acrylic acid) (poly(DVB-co-AA)) hollow microspheres with gold nanoparticles on the interior surfaces were prepared from the gold nanoparticles-coated poly(methacrylic acid) (PMAA@Au@poly(DVB-co-AA)) core-shell microspheres by removal of the PMAA core in water.Au nanoparticles-coated PMAA microspheres were afforded by the in-situ reduction of gold trichloride with PMAA microsphere as stabilizer via the interaction between carboxylic acid groups and Au nanoparticles.Gold nanoparticles-coated (PMAA@Au@poly(DVB-co-AA)) microspheres were formed during the distillation precipitation copolymerization of divinylbenzene and acrylic acid in acetonitrile with Au-coated PMAA microspheres as seeds.The thickness of the poly(DVB-co-AA) shell-layer was controlled by the amount of the solvent distilled off the polymerization system.The PMAA microspheres,Au nanoparticles-coated PMAA microspberes,core-shell microspheres,and hollow microspheres with Au nanoparticles on the interior surfaces were studied by transmission electron microscopy and scanning electron microscopy.The stabilization to L-cysteine and the preliminary catalytic property of the Au nanoparticles on the inner surface of hollow poly(DVB-co-AA) microspheres were investigated.

  16. Advances in the Research and Development of Acrylic Acid Production from Biomass%从生物量生产丙烯酸的研究和开发进展

    许晓波; 林建平; 岑沛霖

    2006-01-01

    The shortage of petroleum has resulted in worldwide efforts to produce chemicals from renewable resources. Among these attempts, the possibility of producing acrylic acid from biomass has caught the eye of many researchers. Converting the carbohydrates first to lactic acid by fermentation and then dehydrating lactic acid to acrylic acid is hitherto the most effective way for producing acrylic acid from biomass. While the lactic acid fermentation has been commercialized since longer times, the dehydration process of lactic acid is still under development because of its low yield. Further efforts should be made before this process became economically feasible.Because of the existence of acrylic acid pathways in some microorganisms, strain improvement and metabolic engineering provides also a possibility to produce acrylic acid directly from biomass by fermentation.

  17. Synthesis of hollow silver spheres using poly-(styrene-methyl acrylic acid) as templates in the presence of sodium polyacrylate

    Wang, Aili; Yin, Hengbo; Ge, Chen; Ren, Min; Liu, Yumin; Jiang, Tingshun

    2010-02-01

    Hollow silver spheres were successfully prepared by reducing AgNO 3 with ascorbic acid and using negatively charged poly-(styrene-methyl acrylic acid) (PSA) spheres as templates in the presence of sodium polyacrylate as a stabilizer. Firstly, silver cations adsorbed on the surface of PSA spheres via electrostatic attraction between the carboxyl groups and silver cations were reduced in situ by ascorbic acid. The silver nanoparticles deposited on the surface of PSA spheres served as seeds for the further growth of silver shells. After that, extra amount of AgNO 3 and ascorbic acid solutions were added to form PSA/Ag composites with thick silver shells. In order to obtain compact silver shells, the as-prepared PSA/Ag composites were heated at 150 °C for 3 h. Then hollow silver spheres were prepared by dissolving PSA templates with tetrahydrofuran.

  18. New liner and reticular polyelectrolytes based an acetoacetic ehter and acrylic acid: synthesis, structure and stimulating sensitivity characteristics

    Novel linear and crosslinked poly-carbolytes based on acetoacetic ester and acrylic acid were synthesized for the first time via Michael addition reaction followed by the radical poly-mineralization. The structure and properties of polyelectrolytes were characterized by FTIR, Raman and NMR spectroscopy, TGA, DSC, GPC, viscosimetry, and potentiometric titration. Considerable influence of water content on the swelling rate of hydrogel was established. The swelling-deswelling properties of hydrogels were studied in water-organic solvent mixtures, electric and magnetic fields. (author)

  19. Characterization of interpenetrating networks of acrylic acid (AAc) and N-isopropylacrylamide (NIPAAm) synthesized by ionizing radiation

    Interpenetrating networks of poly(acrylic acid) (PAAc) and poly(N-isopropylacrylamide) (PNIPAAm) were synthesized in two consecutive steps utilizing ionizing radiation in the first step and chemical reaction in the second step. The first network of PAAc hydrogel was formed by ionizing radiation (gamma or electron beam). The secondary gel of PNIPAAm was synthesized directly within the primary gel of PAAc from an aqueous solution of N-isopropylacrylamide (NIPAAm) containing a crosslinking agent, accelerator and redox initiator. The interpenetrating networks (IPNs) were characterized morphologically by scanning electron microscopy (SEM), and their thermal behavior was analyzed by differential scanning calorimetry (DSC) and thermogravimetry analysis (TGA).

  20. IPN's of Acrylic Acid and N-Isopropylacrylamide by Gamma and Electron Beam Irradiation

    In recent years, temperature and pH sensitive hydrogels have been investigated widely because of their unique properties and versatile applications in medicine and biotechnology, as well as drug delivery. However a serious limitation of hydrogels in many applications is the low mechanical strength of such gels when highly swollen. To overcome this problem, sensitive hydrogels were prepared with satisfactory mechanical properties as a semi-interpenetranting network, where one of them is a mechanically stable polymer. In this work temperature sensitive monomer N-isopropylacrylamide (NIPAAm) and a pH sensitive monomer, acrylic acid (AAc) were prepared as an interpenetranting network by a sequential method. Poly (AAc) hydrogels were prepared in glass tubes 3 mm inner diameter, at room temperature from an aqueous solutions 50%vol under argon atmosphere, and irradiated with a Co60 gamma source, at doses from 5 to 30 kGy and dose rate of 3 kGy/h. Poly (AAc) hydrogels were also prepared by electron beam irradiation with a Van de Graaff at a dose rate of 19.4 kGy/min, and radiation doses from 10 to 30 kGy. After polymerization and crosslinking, the gels were washed in water during 48 h, and dried in vacuo to constant weight. Poly (NIPAAm) as secondary gel was synthetized directly within the primary gels in aqueous solution with the croslinker N, N' methylenebisacrylamide (BIS), the accelerator N,N,N,N tetramethyl ethylenediamidne TMEDA, and potasium persulfate as initiator. Equilibrium swelling properties of hydrogels were studied in pH 2.2-8 range and temperature 10-45degree; LCST and pH critic point of the IPN's were determined; the composition of the interpenetrating network was measured by elemental analysis, and the morphological structure characterized by SEM. The volume of the cells of PAAC hydrogels decreased with increase in radiation dose, their mechanic hardness increased and they lost elasticity. The interpenetrating networks of samples with PAAc irradiated at

  1. Chemically Cross-Linked Poly(acrylic-co-vinylsulfonic Acid Hydrogel for the Delivery of Isosorbide Mononitrate

    Talib Hussain

    2013-01-01

    Full Text Available We report synthesis, characterization, and drug release attributes of a series of novel pH-sensitive poly(acrylic-co-vinylsulfonic acid hydrogels. These hydrogels were prepared by employing free radical polymerization using ethylene glycol dimethacrylate (EGDMA and benzyl peroxide (BPO as cross-linker and initiator, respectively. Effect of acrylic acid (AA, polyvinylsulfonic acid (PVSA, and EGDMA on prepared hydrogels was investigated. All formulations showed higher swelling at high pHs and vice versa. Formulations containing higher content of AA and EGDMA show reduced swelling, but one with higher content of PVSA showed increased swelling. Hydrogel network was characterized by determining structural parameters and loaded with isosorbide mononitrate. FTIR confirmed absence of drug polymer interaction while DSC and TGA demonstrated molecular dispersion of drug in a thermally stable polymeric network. All the hydrogel formulations exhibited a pH dependent release of isosorbide mononitrate which was found to be directly proportional to pH of the medium and PVSA content and inversely proportional to the AA contents. Drug release data were fitted to various kinetics models. Results indicated that release of isosorbide mononitrate from poly(AA-co-VSA hydrogels was non-Fickian and that the mechanism was diffusion-controlled.

  2. Gamma radiation synthesis of comb-type graft hydrogels based on poly(acrylic acid) and 4-vinylpyridine

    A pH-sensitive comb-type hydrogel was obtained by gamma radiation polymerization and crosslinking of acrylic acid (AAc) in solution. The pH-sensitive 4-vinylpyridine (4VP) was then grafted to the poly acrylic acid (PAAc) hydrogel using gamma radiation from a 60Co source. The comb type graft polymers obtained (net-PAAc)-g-4VP has been studied through determination of graft yield and swelling behavior. The critical pH value was found to be 5.6. The apparent mechanical properties appear to be qualitatively better than hydrogels of PAAc upon swelling. The new comb-type system presents faster swelling response (30 h) than the polyacrylic acid hydrogel (50 h). The increase in dose rate from 7.3 to 11.3 kGy h-1, increase the radiation grafting percentage of 4VP in the system. Comb-type polymers were also characterized by DSC, TGA and FTIR-ATR. (author)

  3. Effect of acid additives on graft copolymerization and water absorption of graft copolymers of cassava starch and acrylamide/acrylic acid

    Gelatinized cassava starch was radiation graft copolymerized with acrylamide or acrylic acid in the presence of sulfuric acid, nitric acid or maleic acid at a specific dose rate to a fixed total dose. Homopolymer or free copolymer was extracted by water to obtain the pure graft copolymer, which was subsequently saponified with 5% potassium hydroxide solution at room temperature for 90 min. The saponified graft copolymer was investigated for the effect of acid additives and water absorption. The addition of 2% maleic acid into the grafting reaction containing acrylamide-to-starch ratio of 2.5:1 can produce the superabsorbent copolymer having water absorption as high as 2,256 ± 25 g g-1. The effect of acid additive was explained. (author)

  4. Antibacterial Effect of Acrylic Acid-Grafted Cotton, Wool and Polyester Fabrics on the Growth of Staphylococcus Aureus

    The effects of nutrient time (t) and acrylic acid graft yield (GY) on the growth of Staphylococcus aureus bacteria on cotton, wool and polyester fabrics have been studied. The bacterial growth increases with the increase in t after a 6 h-incubation period (IP). For cotton fabrics, the IP increases from 6 h to 12 h as the GY increases to 20%. The initial growth rate (R) is found to decrease with the increase in graft yield. The order (n) and rate constant (k) of the growth process are calculated at 303 K from the logarithmic dependence of R on GY. Both kinetic parameters are dependent on the type of fabric. The growth rate constant k is the lowest for grafted cotton and the highest for grafted polyester fabrics. The inhibiting effect of grafted poly acrylic acid (PAA), on the S. aureus growth rate is attributed to the release of hydrogen ions (H+) from the grafts into the nutrient aqueous solution. The accumulation of H+ ions, which increase with the increase in GY, at the cell wall and their possible diffusion inside the cell cause a perturbing effect that impairs the viability of the cells. This is observed from the increase in the polysaccharide layer around the cell due to increase in GY to 20%. Transmission electron micrographs revealed the existence of considerable changes in the shape of the cells as a result of PAA grafted on the fabrics

  5. Radiation Synthesis of Poly(N-Vinyl Pyrrolidone) Nanogels and Nanoscale Grafting of Poly(Acrylic Acid) from Cellulose

    Ionizing radiation has long been known to be a very useful tool for the preparation of nanogels. Although preparation is straightforward, the control of the sizes of nanogels has been a challenging issue. This report shows the results of our work on using radiation for the synthesis of PVP nanogels in the range of 40-200nm by making use of the principles of solution thermodynamics of aqueous polymer solutions. Nanoscale grafting of responsive polymers however has been of scientific and industrial importance due to fine control of the molecular weight and molecular weight distribution of grafted polymers. The second part of this report deals with the grafting of poly(acrylic acid) onto the surface of cellulose, thus imparting pH response to the substrate. The use of radiation as a constant source of radical generation and Reversible-Addition-Fragmentation-Chain transfer agents for the control of free radical polymerization provided a full control over the molecular weight and distribution of poly(acrylic acid) grafts on cellulose. (author)

  6. Dye-sensitized solar cell with poly(acrylic acid-co-acrylonitrile)-based gel polymer electrolyte

    Highlights: ► A nontoxic, easily synthesized poly(acrylic acid-co-acrylonitrile) showed suitable transmittance for dye-sensitized solar cell. ► A cell with relatively large active area fabricated with this polymer material showed acceptable efficiency. ► The gel polymer matrix affected the charge recombination, I3− diffusion, double layer capacitance, and electron lifetime in the cell. - Abstract: A non-conducting, nontoxic poly(acrylic acid-co-acrylonitrile) (PAA) was prepared and used as a supporting matrix for the electrolyte of dye-sensitized solar cells (DSSCs). DSSCs of active area 0.80 cm × 1.10 cm fabricated with PAA, 0.5 M LiI, 0.05 M I2, 0.5 M 3-tert-butylpyridine, and 0.1 M 1-methyl-3-propylimidazolium iodide in 3-methoxypropionitrile solvent showed an average solar energy conversion efficiency of 1.61% under simulated sunlight illumination of 100 mW cm−2, AM 1.5. The effects of the gel polymer matrix on the electrochemical properties of DSSCs were studied using the electrochemical impedance spectroscopy. Relative to the non-gel reference cells, the results showed a decrease in charge recombination, ionic diffusion, and double layer capacitance and an increase in electron lifetime. These results could play an important role in determining the future direction for the development of high-performance gel polymer electrolytes.

  7. Controlled release of diclofenac sodium from pH-responsive carrageenan-g-poly(acrylic acid) superabsorbent hydrogel

    Hossein Hosseinzadeh

    2010-07-01

    In this paper, controlled release of diclofenac sodium (DS) from pH-sensitive carrageenan-gpoly(acrylic acid) superabsorbent hydrogels was investigated. The hydrogels were prepared by graft copolymerization of acrylic acid (AA) onto kappa-carrageenan, using ammonium persulfate (APS) as a free radical initiator in the presence of methylene bisacrylamide (MBA) as a crosslinker. Infrared spectroscopy was carried out to confirm the chemical structure of the hydrogel. Moreover, morphology of the samples was examined by scanning electron microscopy (SEM). The synthesized hydrogels were subjected to equilibrium swelling studies in simulated gastric and intestinal fluids (SGF and SIF). Hydrogels containing drug DS, at different drug-to-polymer ratios, were prepared by direct adsorption method. The loading yield was found to depend on both the impregnation time and the amount of encapsulated drug. In vitro drug-release studies in different buffer solutions showed that the most important parameter affecting the drug-release behaviour of hydrogels is the pH of the solution. The mechanism involved in release was Fickian ( ≤ 0.43, = 0.348) and Super Case II kinetics ( > 1, = 1.231) at pH 1.2 and 7.4, respectively.

  8. Ultraviolet-induced surface modification of polyurethane films in the presence of oxygen or acrylic acid vapours

    Weibel, Daniel Eduardo, E-mail: danielw@iq.ufrgs.b [Departamento de Fisico-Quimica, Instituto de Quimica, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil); Fassini Michels, Alexandre [Centro de Ciencias Exatas e Tecnologia, Universidade de Caxias do Sul, Caxias do Sul, RS (Brazil); Horowitz, Flavio [Laser and Film Optics Laboratory, Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil); Silva Cavalheiro, Ricardo da [Departamento de Fisico-Quimica, Instituto de Quimica, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil); Vingre da Silva Mota, Gunar [Curso de Fisica, Universidade Federal do Amapa, Macapa, AP (Brazil)

    2009-07-31

    An efficient surface functionalization of polyurethane (PU) films has been obtained by ultraviolet (UV)-assisted modification in the presence of oxygen or acrylic acid (AA) vapours. Film analyses were carried out by water contact angle measurements, X-ray photoelectron spectroscopy (XPS) and Near-edge X-ray absorption fine structure (NEXAFS). Film hydrophilicity increased with photolysis time in the presence of oxygen or AA vapours. Incorporation of COO and C=O functional groups at the polymer surface after the UV-assisted treatments was observed. In addition, High resolution XPS and NEXAFS results showed that a thin film of poly (acrylic acid) (PAA) is formed over the PU films during the UV irradiation with AA vapours. The obtained results are compared with previous published oxygen and AA low-power plasma treatments. Similarity between both treatment methodologies is shown. UV surface functionalization and polymerization of PAA can be used instead of a traditional plasma treatment with the advantage of set-up simplicity and lower costs.

  9. Ultraviolet-induced surface modification of polyurethane films in the presence of oxygen or acrylic acid vapours

    An efficient surface functionalization of polyurethane (PU) films has been obtained by ultraviolet (UV)-assisted modification in the presence of oxygen or acrylic acid (AA) vapours. Film analyses were carried out by water contact angle measurements, X-ray photoelectron spectroscopy (XPS) and Near-edge X-ray absorption fine structure (NEXAFS). Film hydrophilicity increased with photolysis time in the presence of oxygen or AA vapours. Incorporation of COO and C=O functional groups at the polymer surface after the UV-assisted treatments was observed. In addition, High resolution XPS and NEXAFS results showed that a thin film of poly (acrylic acid) (PAA) is formed over the PU films during the UV irradiation with AA vapours. The obtained results are compared with previous published oxygen and AA low-power plasma treatments. Similarity between both treatment methodologies is shown. UV surface functionalization and polymerization of PAA can be used instead of a traditional plasma treatment with the advantage of set-up simplicity and lower costs.

  10. Preparation of acrylic acid-modified chitin improved by an experimental design and its application in absorbing toxic organic compounds

    Huang, Chao-Ming, E-mail: charming@mail.ksu.edu.tw [Department of Materials Engineering, Kun Shan University, Tainan, Taiwan (China); Chen, Lung-Chuan, E-mail: lcchen@mail.ksu.edu.tw [Department of Materials Engineering, Kun Shan University, Tainan, Taiwan (China); Yang, Hui-Chia, E-mail: yang.junkdna@gmail.com [Department of Environmental Engineering, Kun Shan University, Tainan, Taiwan (China); Li, Min-Hsing, E-mail: a1487561a@yahoo.com.tw [Department of Environmental Engineering, Kun Shan University, Tainan, Taiwan (China); Pan, Ting-Chung, E-mail: tcpan@mail.ksu.edu.tw [Department of Environmental Engineering, Kun Shan University, Tainan, Taiwan (China)

    2012-11-30

    Highlights: Black-Right-Pointing-Pointer Acrylic acid-modified chitin. Black-Right-Pointing-Pointer Experimental design. Black-Right-Pointing-Pointer Graft copolymerization. Black-Right-Pointing-Pointer Adsorption of toxic organic compounds. Black-Right-Pointing-Pointer Very high adsorption capacity. - Abstract: Chitin grafted poly (acrylic acid) (chi-g-PAA) is synthesized and characterized as an adsorbent of toxic organic compounds. Chi-g-PAA copolymers are prepared using of ammonium cerium (IV) nitrate (Ce{sup 4+}) as the initiator. The highest grafting percentage of AA in chitin obtained using the traditional technique is 163.1%. A maximum grafting percentage of 230.6% is obtained using central composite design (CCD). Experimental results are consistent with theoretical calculations. The grafted copolymer is characterized by Fourier transform Infrared spectroscopy and solid state {sup 13}C NMR. A representative chi-g-AA copolymer is hydrolyzed to a type of sodium salt (chi-g-PANa) and used in the adsorption of malachite green (MG), methyl violet (MV), and paraquat (PQ) in aqueous. The monolayer adsorption capacities of these substances are 285.7, 357.1, and 322.6 mg/g-adsorbent, respectively. Thermodynamic calculations show that the adsorption of MG, MV, and PQ are more favored at diluted solutions. The high adsorption capacity of chi-g-PANa for toxic matter indicates its potential in the treatment of wastewater and emergency treatment of PQ-poisoned patients.

  11. Poly (acrylic acid sodium) grafted carboxymethyl cellulose as a high performance polymer binder for silicon anode in lithium ion batteries.

    Wei, Liangming; Chen, Changxin; Hou, Zhongyu; Wei, Hao

    2016-01-01

    The design of novel binder systems is required for the high capacity silicon (Si) anodes which usually undergo huge volume change during the charge/discharge cycling. Here, we introduce a poly (acrylic acid sodium)-grafted-carboxymethyl cellulose (NaPAA-g-CMC) copolymer as an excellent binder for Si anode in lithium ion batteries (LIBs). The NaPAA-g-CMC copolymer was prepared via a free radical graft polymerization method by using CMC and acrylic acid as precursors. Unlike the linear, one-dimensional binders, the NaPAA-g-CMC copolymer binder is expected to present multi-point interaction with Si surface, resulting in enhanced binding ability with Si particles as well as with the copper (Cu) current collectors, and building a stable solid electrolyte interface (SEI) layer on the Si surface. The NaPAA-g-CMC based Si anode shows much better cycle stability and higher coulombic efficiency than those made with the well-known linear polymeric binders such as CMC and NaPPA. PMID:26786315

  12. Preparation, characterization, and antibacterial activity studies of silver-loaded poly(styrene-co-acrylic acid) nanocomposites

    Song, Cunfeng [Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005 (China); Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (China); Chang, Ying; Cheng, Ling; Xu, Yiting [Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005 (China); Chen, Xiaoling, E-mail: tinachen0628@163.com [Department of Endodontics, Xiamen Stomatology Hospital, Teaching Hospital of Fujian Medical University, Xiamen 361003 (China); Zhang, Long; Zhong, Lina [Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005 (China); Dai, Lizong, E-mail: lzdai@xmu.edu.cn [Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005 (China)

    2014-03-01

    A simple method for preparing a new type of stable antibacterial agent was presented. Monodisperse poly(styrene-co-acrylic acid) (PSA) nanospheres, serving as matrices, were synthesized via soap-free emulsion polymerization. Field-emission scanning electron microscopy micrographs indicated that PSA nanospheres have interesting surface microstructures and well-controlled particle size distributions. Silver-loaded poly(styrene-co-acrylic acid) (PSA/Ag-NPs) nanocomposites were prepared in situ through interfacial reduction of silver nitrate with sodium borohydride, and further characterized by transmission electron microscopy and X-ray diffraction. Their effects on antibacterial activity including inhibition zone, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and bactericidal kinetics were evaluated. In the tests, PSA/Ag-NPs nanocomposites showed excellent antibacterial activity against both gram-positive Staphylococcus aureus and gram-negative Escherichia coli. These nanocomposites are considered to have potential application in antibacterial coatings on biomedical devices to reduce nosocomial infection rates. - Highlights: • A new type of antibacterial agent (PSA/Ag-NPs nanocomposites) was synthesized. • The antibacterial activity against S. aureus and E. coli was studied. • Inhibition zone, MIC, MBC, and bactericidal kinetics were evaluated. • PSA/Ag-NPs nanocomposites showed excellent antibacterial activity.

  13. Preparation, characterization, and antibacterial activity studies of silver-loaded poly(styrene-co-acrylic acid) nanocomposites

    A simple method for preparing a new type of stable antibacterial agent was presented. Monodisperse poly(styrene-co-acrylic acid) (PSA) nanospheres, serving as matrices, were synthesized via soap-free emulsion polymerization. Field-emission scanning electron microscopy micrographs indicated that PSA nanospheres have interesting surface microstructures and well-controlled particle size distributions. Silver-loaded poly(styrene-co-acrylic acid) (PSA/Ag-NPs) nanocomposites were prepared in situ through interfacial reduction of silver nitrate with sodium borohydride, and further characterized by transmission electron microscopy and X-ray diffraction. Their effects on antibacterial activity including inhibition zone, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and bactericidal kinetics were evaluated. In the tests, PSA/Ag-NPs nanocomposites showed excellent antibacterial activity against both gram-positive Staphylococcus aureus and gram-negative Escherichia coli. These nanocomposites are considered to have potential application in antibacterial coatings on biomedical devices to reduce nosocomial infection rates. - Highlights: • A new type of antibacterial agent (PSA/Ag-NPs nanocomposites) was synthesized. • The antibacterial activity against S. aureus and E. coli was studied. • Inhibition zone, MIC, MBC, and bactericidal kinetics were evaluated. • PSA/Ag-NPs nanocomposites showed excellent antibacterial activity

  14. Physicochemical properties of poly(lactic acid-co-glycolic acid film modified via blending with poly(butyl acrylate-co-methyl methacrylate

    Guoquan Zhu

    2013-01-01

    Full Text Available A series of poly(lactic acid-co-glycolic acid (PLGA/poly(butyl acrylate-co-methyl methacrylate (P(BA-co-MMA blend films with different P(BA-co-MMA mole contents were prepared by casting the polymer blend solution in chloroform. Surface morphologies of the PLGAP(BA-co-MMA blend films were studied by scanning electron microscopy (SEM. Thermal, mechanical, and chemical properties of PLGAP(BA-co-MMA blend films were investigated by differential scanning calorimeter (DSC, thermogravimetric analysis (TGA, tensile tests, and surface contact angle tests. The introduction of P(BA-co-MMA could modify the properties of PLGA films.

  15. The Chemical and Physical Properties of Poly( ε -caprolactone) Scaffolds Functionalised with Poly(vinyl phosphonic acid-co-acrylic acid)

    Bassi, A. K.; Gough, J. E.; Zakikhani, M.; Downes, S

    2011-01-01

    There is a clinical need for a synthetic alternative to bone graft substitute (BGS) derived from demineralised bone matrix. We report the electrospinning of Poly(ε-caprolactone) (PCL) to form a 3-dimensional scaffold for use as a synthetic BGS. Additionally, we have used Poly(vinyl phosphonic acid-co-acrylic acid) (PVPA) to improve bone formation. Fibres were formed using a 10% w/v PCL/acetone solution. Infrared spectroscopy confirmed that the electrospinning process had no effect on the func...

  16. NaY zeolites modified by La~(3+) and Ba~(2+): the effect of synthesis details on surface structure and catalytic performance for lactic acid to acrylic acid

    闫婕; 余定华; 李恒; 孙鹏; 黄和

    2010-01-01

    Modified NaY zeolites have been widely studied and the modification metal element is normally single, while few researches have been conducted on NaY zeolites modified by two kinds of metals. In our study, a series of La3+ and Ba2+ modified NaY zeolites were synthesized through different impregnation procedures. Lactic acid dehydration to acrylic acid was selected as a probe reaction to test the catalytic performance of these zeolites synthesized. The effects of synthesis details on their pore structures an...

  17. Preparation and characterization of polyacrylamide-modified kaolinite containing poly [acrylic acid-co-methylene bisacrylamide] nanocomposite hydrogels

    Zaharia, Anamaria; Sarbu, Andrei; Radu, Anita-Laura;

    2015-01-01

    Novel nanocomposite hydrogel structures based on cross-linked poly(acrylic acid) (PAA) and kaolinite (Kaol), modified with different loadings of polyacrylamide (PAAm), were prepared by inverse dispersion polymerization. Ceric ammonium nitrate as an initiator in the presence of nitric acid was used...... to graft PAAm from the Kaol surface. The surface-modified Kaol showed enhanced interactions between the filler and the PAA matrix, through interactions between amino (-NH2) from PAAm and carboxylic groups (-COOH) from PAA. The XRD and TEM measurements confirmed the exfoliated nanocomposites with the...... Kaol filler. The swelling degree (SD) of the swollen hydrogel nanocomposite was increased following the addition of polyacrylamide-modified Kaol particles into the hydrogel structures. Rheological characterization showed that an increase in the storage modulus (G') could be a consequence of a good...

  18. Effect of time and temperature exposition in the crystallinity degree of sulfonated poly-(styrene acrylic acid) (PSAA-S)

    Duarte, G.W.; Becker, E.B.; Silva, L.; Naspolini, A.M.; Consenso, E.C.; Paula, M.M.S.; Fiori, M.A., E-mail: glau_bn@hotmail.co [University of Extreme South of Santa Catarina Criciuma, SC (Brazil). Dept. of Materials Engineering; Silveira, F.Z. [Federal University of Santa Catarina (UFSC), Florianopolis, SC (Brazil). Dept. of Chemical Engineering

    2010-07-01

    Polymers with special properties have been increasingly applied in the development of technological devices. For example, polymeric materials with special electric properties, such as sulfonated poly-(styrene-acrylic acid) - PSAA-S, are of great interest for showing different conductivities depending on the environment where they are applied. The special properties of PSAA are obtained only after sulfonation step in acidic media. The present work aimed to evaluate the effect of time and temperature exposition in the crystallinity degree of PSAA-S, through a statistical experimental factorial planning. The samples of PSAA-S were submitted to FT-IR and DRX tests. The results showed that the temperature and the time of exposition are significant factors in the crystallinity degree of PSAA-S, considering that the crystal lattices created during the polymerization are damaged by the action of time and temperature at which the polymer is exposed. (author)

  19. Characterization of pH-sensitive Poly (acrylic acid-co-N-vinyl-2-pyrrolidone) Hydrogels Prepared by Gamma Radiation

    YANG Ming-cheng; HE Su-qin; LIU Wen-tao; SONG Hong-yan; ZHU Cheng-shen

    2007-01-01

    The pH-sensitive copolymer hydrogels were prepared with the monomers of acrylic acid and N-vinyl-2-pyrrolidone based on gamma radiation technique. The morphology of the hydrogels was monitored by using scanning electron microscope. The influence of absorbed dose, monomer compasition and concentration on the swelling ratio (SR) of the hydrogels were investigated in detail. The effect of pH and temperature of the swelling medium on the swelling behavior of the hydrogels were also examined. The results show that the SR of the copolymer hydrogels decreases with the monomer concentration and absorbed dose increasing. The copolymer hydrogels show a better pH-sensitive behavior. In alkaline solution, the SR of the hydrogels is much higher than in acid solution.

  20. Oral delivery of insulin using pH-sensitive hydrogels based on polyvinyl alcohol grafted with acrylic acid/methacrylic acid by radiation

    The pH-responsive hydrogels were studied as a drug carrier for the protection of insulin from the acidic environment of the stomach before releasing in the small intestine. Hydrogels based on poly(vinyl alcohol) networks grafted with acrylic acid or methacrylic acid were prepared via a two-step process. Poly(vinyl alcohol) hydrogels were prepared by gamma ray irradiation (50 kGy) and then followed by grafting either acrylic acid or methacrylic acid onto this poly(vinyl alcohol) hydrogels with subsequent irradiation (5-20 kGy). These graft hydrogels showed pH-sensitive swelling behavior. These hydrogels were used as carrier for the controlled release of insulin. The in vitro release of insulin was observed for the insulin-loaded hydrogels in a simulated intestinal fluid (pH 6.8) but not in a simulated gastric fluid (pH 1.2). The release behavior of insulin in vivo in a rat model confirmed the effectiveness of the oral delivery of insulin to control the level of glucose

  1. Preparation and drug-loading properties of Fe{sub 3}O{sub 4}/Poly(styrene-co-acrylic acid) magnetic polymer nanocomposites

    Lu, Wensheng [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China); Coordination Chemistry Institute, School of Chemistry and Chemical Engineering and Life Science, Chaohu University, Chaohu 238000 (China); Shen, Yuhua, E-mail: s_yuhua@163.com [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China); Xie, Anjian [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China); Zhang, Weiqiang [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China); Coordination Chemistry Institute, School of Chemistry and Chemical Engineering and Life Science, Chaohu University, Chaohu 238000 (China)

    2013-11-15

    Fe{sub 3}O{sub 4}/poly(styrene-co-acrylic acid) magnetic polymer nanocomposites were synthesized by the dispersion polymerization method using styrene as hard monomer, acrylic acid as functional monomer, Fe{sub 3}O{sub 4} nanoparticles modified with oleic acid as core, and poly(styrene-co-acrylic acid) as shell. Drug-loading properties of magnetic polymer nanocomposites with curcumin as a model drug were also studied. The results indicated that magnetic polymer nanocomposites with monodisperse were obtained, the particle size distribution was 50–120 nm, and the average size was about 100 nm. The contents of poly(styrene-co-acrylic acid) and Fe{sub 3}O{sub 4} nanoparticles in magnetic polymer nanocomposites were 74% and 24.7%, respectively. The drug-loading capacity and entrapment efficiency were 2.5% and 44.4%, respectively. The saturation magnetization of magnetic polymer nanocomposites at 300 K was 20.2 emu/g without coercivity and remanence. The as-prepared magnetic polymer nanocomposites have not only lots of functional carboxyl groups but also stronger magnetic response, which might have potential applications in drug carrier and targeted drug release.

  2. A new coordination mode of (E)-3-(3-hydroxyl-phenyl)-acrylic acid in copper complex: Crystal structure and magnetic properties

    Jin, Xin; Zhou, Pei; Zheng, Chunying [Key Laboratory of Cluster Science of Ministry of Education, School of Chemistry, Beijing Institute of Technology, Beijing 100081 (China); Li, Hui, E-mail: lihui@bit.edu [Key Laboratory of Cluster Science of Ministry of Education, School of Chemistry, Beijing Institute of Technology, Beijing 100081 (China)

    2015-05-15

    A copper complex ([Cu(py){sub 2}(L){sub 2}]·2CH{sub 3}OH){sub n} (HL=(E)-3-(3-hydroxyl-phenyl)-acrylic acid) (1) with acrylic acid ligand was synthesized and structurally analyzed by IR, elemental analysis, TGA and the single-crystal X-ray diffraction methods. It is the first time to find that phenolic hydroxyl of L coordinates to Cu(II). Complex 1 exhibits 1D chain by a double-bridge of ligands, and the 3D supramolecular framework in complex 1 is constructed by π–π stacking interactions and van der Waals Contacts among the 1D chains. The magnetic properties of complex 1 have been studied. - Graphical abstract: A copper complex based on (E)-3-(3-hydroxyl-phenyl)-acrylic acid in a novel coordinated way was synthesized and a ferromagnetic exchange interactions between neighboring Cu(II) ions has be achieved. - Highlights: • A new copper complex with acrylic acid ligand was synthesized and analyzed. • We find the phenolic hydroxyl of MCA ligand coordinates to metal ion firstly. • A ferromagnetic exchange interactions between Cu(II) ions has been achieved.

  3. A new coordination mode of (E)-3-(3-hydroxyl-phenyl)-acrylic acid in copper complex: Crystal structure and magnetic properties

    A copper complex ([Cu(py)2(L)2]·2CH3OH)n (HL=(E)-3-(3-hydroxyl-phenyl)-acrylic acid) (1) with acrylic acid ligand was synthesized and structurally analyzed by IR, elemental analysis, TGA and the single-crystal X-ray diffraction methods. It is the first time to find that phenolic hydroxyl of L coordinates to Cu(II). Complex 1 exhibits 1D chain by a double-bridge of ligands, and the 3D supramolecular framework in complex 1 is constructed by π–π stacking interactions and van der Waals Contacts among the 1D chains. The magnetic properties of complex 1 have been studied. - Graphical abstract: A copper complex based on (E)-3-(3-hydroxyl-phenyl)-acrylic acid in a novel coordinated way was synthesized and a ferromagnetic exchange interactions between neighboring Cu(II) ions has be achieved. - Highlights: • A new copper complex with acrylic acid ligand was synthesized and analyzed. • We find the phenolic hydroxyl of MCA ligand coordinates to metal ion firstly. • A ferromagnetic exchange interactions between Cu(II) ions has been achieved

  4. Poly(glycidyl methacrylate) microspheres: preparation by poly(acrylic acid)-stabilized dispersion polymerization and effect of some reaction parameters

    Koubková, Jana; Horák, Daniel

    2013-01-01

    Roč. 2, č. 3 (2013), s. 218-225. ISSN 2164-9634 R&D Projects: GA ČR GCP207/12/J013 Institutional support: RVO:61389013 Keywords : glycidyl methacrylate * dispersion polymerization * poly(acrylic acid) Subject RIV: CD - Macromolecular Chemistry

  5. Systematic investigation of the synthesis of core-shell poly(styrene-co-acrylic acid) colloids with varying shell thickness and core diameter

    Hinge, Mogens; Keiding, Kristian

    2006-01-01

    (acrylic acid). Further the TEM images of the colloids supported the core-shell morphology of the produced poly(ST-co-AA) colloids. This shows that the produced poly(ST-co-AA) colloids have a core-shell morphology and that the shell thickness can be increased by increasing the acrylic acid concentration in the...... morphology of the material for an specific application is going on. It is known from SFEP of styrene that the final colloidal size can be controlled by adjusting the ionic strength of the synthesis feed [1] and it is suggested that adding acrylic acid to the synthesis will result in a change in...... determined as a function of time. Results show a shift in polymerization from styrene in the core to acrylic acid at the surface during the synthesis. This gives poly(ST-co-AA) colloids that has a core-shell morphology with a core mainly consisting of poly(styrene) and a shell mainly consisting of poly...

  6. Thermosensitive membranes by radiation-induced graft polymerization of N-isopropyl acrylamide/acrylic acid on polypropylene nonwoven fabric

    Radiation-induced graft copolymerization of N-isopropylacrylamide (NIPAAm) and acrylic acid (AA) mixture was investigated on polypropylene nonwoven fabric to develop a thermosensitive material. The grafting was carried out using methanol, acetone and butanone as homopolymerization inhibitor in the reaction medium. Butanone was observed to give the maximum grafting. It was observed that the grafting is significantly influenced by the reaction conditions, such as radiation dose, monomer concentration, monomer ratio, solvent composition and reaction temperature. The degree of grafting increased as the AA and NIPAAm concentration in the reaction medium increased. The degree of grafting increased as the AA fraction in the NIPAAm/AA mixture increased. The temperature dependence of the grafting process is very much governed by the thermosensitive nature of the grafted chains right from the stage when initial grafting has taken place.

  7. Radiation synthesis of pH-sensitive hydrogels from β-cyclodextrin-grafted PEG and acrylic acid for drug delivery

    A water-soluble macromonomer (PEG-β-CD) was synthesised by reaction of β-cyclodextrin with poly(ethylene glycol) diglycidyl ether. Then, a novel hydrogel with pH-sensitivity was prepared by irradiating the mixture of acrylic acid and PEG-β-CD with electron beam. Compared with the normal PAAc hydrogel, this novel hydrogel had a higher swelling ratio at pH 3-8. 5-Fluorouracil (5-FU) was chosen as a model drug, and the kinetics of 5-FU releasing behavior was studied. Compared with the PAAc hydrogel, the results showed the release time of 5-FU from the cyclodextrin containing hydrogel was prolonged. It may be ascribed to the formation of inclusion complexes between the drug molecules and cyclodextrin groups.

  8. An interesting grafting reactivity of EB preirradiated polypropylene film[Radiation grafting; Polypropylene; Free radical; peroxide; Acrylic acid; Acrylamide

    Chen Jie E-mail: chenjjd@online.sh.cn; Yang Liming; Chen Liqin; Wu Minhong; Nho, Y.C.; Kaetsua, Isao

    2004-02-01

    An interesting grafting reactivity of electron beam preirradiated polypropylene (PP) film was found by grafting of acrylic acid (AAc) and acrylamide (AAm) repeatedly or intermittently. The preirradiated PP film could be grafted several times intermittently and the free radicals or peroxides on the samples could be determined after several times grafting reaction. The effects of storage time, reaction time and repeated reaction times on the degree of grafting were investigated. The trapped radicals, peroxy-radicals and peroxides on the preirradiated and reacted PP films were determined by using electron spin resonance (ESR) and 1,1-diphenyl-2-picryl hydrazyl (DPPH), respectively. An interpenetrating polymer networks (IPN) with both temperature and pH sensitive properties was obtained by two times grafting of AAm and AAc onto preirradiated PP film.

  9. A study on the swelling behavior of poly(acrylic acid) hydrogels obtained by electron beam crosslinking

    Sheikh, N., E-mail: nasheikh@aeoi.org.i [Radiation Applications Research School, Nuclear Science and Technology Research Institute, P.O. Box 11365-3486, Tehran (Iran, Islamic Republic of); Jalili, L. [Polymer group, Technology and Engineering Department, Yazd University, Yazd (Iran, Islamic Republic of); Anvari, F. [Radiation Applications Research School, Nuclear Science and Technology Research Institute, Yazd (Iran, Islamic Republic of)

    2010-06-15

    Poly(acrylic acid) (PAA) hydrogels were prepared by using electron beam (EB) crosslinking of PAA homopolymer from its aqueous solutions. The swelling behavior of the hydrogels was studied as a function of the concentration of PAA solution, radiation dose, pH of the swelling medium and swelling time. Also the environmental pH effect on the water diffusion mode into hydrogels was investigated. These hydrogels clearly showed pH-sensitive swelling behavior with Fickian type of diffusion in the stomach-like pH medium (pH 1.3) and non-Fickian type in the intestine-like pH medium (pH 6.8).

  10. Surface grafted chitosan gels. Part I. Molecular insight into the formation of chitosan and poly(acrylic acid) multilayers

    Liu, Chao; Thormann, Esben; Claesson, Per M.;

    2014-01-01

    Composite polyelectrolyte multilayers of chitosan and low molecular weight poly(acrylic acid) (PAA) have been assembled by sequential adsorption as a first step toward building a surface anchored chitosan gel. Silane chemistry was used to graft the first chitosan layer to prevent film detachment...... and decomposition. The assembly process is characterized by nonlinear growth behavior, with different adsorption kinetics for chitosan and PAA. In situ analysis of the multilayer by means of surface sensitive total internal reflection Raman (TIRR) spectroscopy, combined with target factor analysis of...... steps. The higher molecular weight chitosan shows a similar behavior, although to a much lower extent. Our data demonstrate that the charged monomeric units of chitosan are mainly compensated by carboxylate ions from PAA. Furthermore, the morphology and mechanical properties of the multilayers were...

  11. Preparation of poly(polyethylene glycol methacrylate-co-acrylic acid) hydrogels by radiation and their physical properties

    The pH-responsive copolymer hydrogels were prepared with the monomers of polyethylene glycol methacrylate and acrylic acid based on γ-ray irradiation technique. The gel content of these copolymer hydrogels varied depending on both the composition of monomers and the radiation dose. Maximum gel percent and degree of crosslinking were obtained at the composition of equal amount of comonomers. These copolymer hydrogels did not show any noticeable change in swelling at lower pH range. However they showed an abrupt increase in swelling at higher pH range due to the ionization of carboxyl groups. This pH-responsive swelling behavior was applied for the insulin carrier via oral delivery. Insulin-loaded copolymer hydrogels released most of their insulin in the simulated intestinal fluid which had a pH of 6.8 but not in the simulated gastric fluid which had a pH of 1.2

  12. PHOTO-INDUCED DOPED POLYANILINE BY THE VINYLIDENE CHLORIDE AND METHYL ACRYLATE COPOLYMER AS PHOTO ACID GENERATOR

    LI Suzhen; WAN Meixiang

    1997-01-01

    The emeraldine base form of polyaniline (PANI) can be doped by a photo-induced doping method. In this method a copolymer of vinylidene chloride and methyl acrylate (VCMAC) was used as photo acid generator which can release proton when it is exposed to ultraviolet light (λ = 254 nm). The structure of PANI-VCMAC system before and after irradiation was characterized by elemental analysis, IR, XPS, and SEM images. Results obtained indicate that the photo-induced doping characteristics, such as doping position and type of charge carriers, are similar to that of PANI doped with HCl. The poor roomtemperature conductivity (~ 10-5S/cm) of PANI-VCMAC system after irradiation may be due to low doping degree (~pH= 3) and the difference in morphology as compared with PANI-HCl film.

  13. Removal of reactive dyes from textile wastewater by immobilized chitosan upon grafted Jute fibers with acrylic acid by gamma irradiation

    Hassan, Mahmoud S.

    2015-10-01

    Jute fibers were grafted with acrylic acid by gamma irradiation technique. Chitosan was immobilized upon the grafted Jute fibers to be used as an adsorbent for waste reactive dye. The treated Jute fibers were characterized by using of Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and X-ray diffraction (XRD). The effect of Jute treatment on its thermal stability by using thermogravimetric analysis (TGA) and its mechanical properties were investigated. The adsorption isotherm and the different factors affecting the dye adsorption such as pH and contact time were also studied. It was found that the dye adsorption was enhanced in the low pH range and increased with increasing of the contact time, regardless of temperature change.

  14. Preparation and characterization of ZnS/poly(acrylamide-co-acrylic acid) dendritical nanocomposites by γ-irradiation

    Zinc sulfide poly(acrylamide-co-acrylic acid) [ZnS/P(AM-co-AA)] nanocomposites with a dendritical structure were successfully prepared in one step by γ-irradiation technique in an aqueous system at room temperature and under ambient pressure. The results from X-ray powder diffraction (XRD) analysis and IR spectrum of the final product showed the formation of ZnS nanoparticles and the polymerization of monomers, respectively. The photoluminescence (PL) peak of the as-prepared product centered at 450 nm, which showed an obvious red shift compared with the ZnS bulk material. The presence of copolymer was considered to be the main reason that influenced the shape and photoluminescence property of the composite

  15. Improvement in the behavior of bromelain coupled to pNIPAm polymers containing acrylamide or acrylic acid

    Rubab Mahmood

    2014-08-01

    Full Text Available Bromelain was coupled to N-isopropyl acrylamide (NIPAmpolymers, synthesized using NIPAm and various concentrations of acrylamide (Ac or acrylic acid (AAc. Incorporation of Ac/AAcinto the polymer increased the LCST (lower critical solutiontemperature in a concentration dependent manner but AAc wasmore effective in this regard; the LCST rose to 40°C when 6 percent AAc was used. Incorporation of Ac/AAc increased the coupling of enzyme to the polymer and the η (effectiveness factor of the coupled enzyme, moderately. Various studies indicate that such incorporation of hydrophilic monomers into the polymer does not impair its capacity to couple enzyme or expression of the activity of bound enzyme but seems to actually improve the stability of the enzyme against heat induced inactivation and alkaline pH.

  16. Tensile properties of low density polypropylene (LDPE)/palm kernel shell (PKS) biocomposites: The effect of acrylic acid (AA)

    The surface of palm kernel was modified by acrylic acid (AA). Low density polyethylene (LDPE) was filled by palm kernel shell at various 0, 10, 20, 30 and 40 php. The effect of AA as a coupling agent on LDPE/PKS biocomposites on tensile properties and morphology was investigated. The results show that the increasing of filler content decreased the tensile strength and break elongation but increased the Young's modulus. The presence of AA indicates higher tensile strength and Young's modulus but lower elongation at break compared to untreated LDPE/PKS biocomposites. The scanning electron microscope study show that the better interfacial interaction between palm kernel shell and low density polyethylene with addition of AA.

  17. Effect of thermal treatment conditions on properties of vanadium molybdenum oxide catalyst in acrolein oxidation reaction to acrylic acid

    The effect of thermal treatment conditions (temperature and gas medium) on properties of vanadium molybdenum oxide catalyst in acrolein oxidation reaction to acrylic acid is investigated. It is shown that active and selective catalysts are formed in the course of thermal decomposition of the drying product of ammonium metavanadate and paramolybdate under the conditions ensuring the vanadium ion reduction up to tetravalent state with conservation of molybdenum oxidation degree equal to 6. It is possible to realize it either by treatment of the catalyst calcinated in the air flow at 300 deg by the reaction mixture at the activation stage or by gas-reducer flow treatment at 280 deg. Thermal treatment in the reducing medium of the oxidized catalyst does not lead to complete regeneration of its properties

  18. SYNTHESIS OF SOAP-FREE ACRYLIC HYDROSOLS

    Li Jia; Zong-hui Liu; De-qing Wei

    2002-01-01

    Poly(methyl methacrylate/ethyl acrylate/acrylic acid) hydrosols were prepared by employing soap-freepolymerization, and (acrylic acid/butyl acrylate) oligomer was used as the polymeric surfactant. The effect of reactioncondition on the morphology and particle size of the hydrosols was investigated. The minimum amount of acrylic acid in thehydrosols is 2%. The maximum weight average molecular weight (Mw) of polymer that assures soap-free emulsionconversion into hydrosol is about 1.2 × 105-1.3 × 105. The particle transforming process was investigated, and an obviouschange of particle diameter and morphology was observed.

  19. Preparation and characterization of mucus-penetrating papain/poly(acrylic acid) nanoparticles for oral drug delivery applications

    Mueller, Christiane; Leithner, Katharina; Hauptstein, Sabine; Hintzen, Fabian [Center for Molecular Biosciences Innsbruck, University of Innsbruck, CCB-Centrum for Chemistry und Biomedicine, Department of Pharmaceutical Technology, Institute of Pharmacy (Austria); Salvenmoser, Willi [University of Innsbruck, Department for Evolutionary Developmental Biology, Institute of Zoology and Center for Molecular Biosciences (Austria); Bernkop-Schnuerch, Andreas, E-mail: andreas.bernkop@uibk.ac.at [Center for Molecular Biosciences Innsbruck, University of Innsbruck, CCB-Centrum for Chemistry und Biomedicine, Department of Pharmaceutical Technology, Institute of Pharmacy (Austria)

    2013-01-15

    Particle diffusion through the intestinal mucosal barrier is restricted by the viscoelastic and adhesive properties of the mucus gel layer, preventing their penetration to the underlying absorptive endothelial cells. To overcome this natural barrier, we developed nanoparticles which have a remarkable ability to cleave mucoglycoprotein substructures responsible for the structural and rheological properties of mucus. After rheological screening of various mucolytic proteases, nanoparticles composed of poly(acrylic acid) and papain were prepared and characterized regarding particle size and zeta potential. Analysis of nanoparticles showed mean diameters sub-200 nm (162.8-198.5 nm) and negative zeta potentials advancing the mobility in mucus gel. Using diffusion chamber studies and the rotating diffusion tubes method, we compared the transport rates of papain modified (PAPC) and unaltered poly(acrylic acid) (PAA) particles through freshly excised intestinal porcine mucus. Results of the diffusion assays demonstrated strongly enhanced permeation behavior of PAPC particles owing to local mucus disruption by papain. Improved transport rates, reduction in mucus viscosity and the retarded release of hydrophilic macromolecular compounds make proteolytic enzyme functionalized nanoparticles of substantial interest for improved targeted drug delivery at mucosal surfaces. Although cytotoxicity tests of the nanoparticles could not be performed, safety of papain and PAA was already verified making PAPC particles a promising candidate in the pharmaceutical field of research. The focus of the present study was the development of particles which penetrate the mucus barrier to approach the underlying epithelium. Improvements of particles that penetrate the mucus followed by cell uptake in this direction are ongoing.

  20. Calcium Phosphate Mineralization in Cellulose Derivative/Poly(acrylic acid) Composites Having a Chiral Nematic Mesomorphic Structure.

    Ogiwara, Takuya; Katsumura, Ayaka; Sugimura, Kazuki; Teramoto, Yoshikuni; Nishio, Yoshiyuki

    2015-12-14

    Calcium phosphate mineralization was conducted by using polymer composites of liquid-crystalline (ethyl)cellulose (EC) or (hydroxypropyl)cellulose (HPC) with poly(acrylic acid) (PAA) as a scaffolding medium for the inorganic deposition. The EC/PAA and HPC/PAA samples were prepared in colored film form from EC and HPC lyotropic liquid crystals of left-handed and right-handed chiral nematics, respectively, by polymerization and cross-linking of acrylic acid as the main solvent component. The mineralization was allowed to proceed in a batchwise operation by soaking the liquid-crystalline films in an aqueous salt solution containing the relevant ions, Ca(2+) and HPO4(2-). The calcium phosphate-deposited EC/PAA and HPC/PAA composites (weight gain, typically 15-25% and 6-11%, respectively) retained the chiral nematic organization of the respective original handedness but exhibited selective light-reflection of longer wavelengths relative to that of the corresponding nonmineralized samples. From X-ray diffraction and energy-dispersive X-ray spectroscopy measurements, it was deduced that the calcium and phosphorus were incorporated inside the polymer matrices in three forms: amorphous calcium phosphate, hydroxyapatite, and a certain complex of PAA-Ca(2+). Dynamic mechanical analysis and thermogravimetry revealed that the inorganic hybridization remarkably enhanced the thermal and mechanical performance of the optically functionalized cellulosic/synthetic polymer composites; however, the effect was more drastic in the EC/PAA series rather than the HPC/PAA series, reflecting the difference in the deposited mineral amount between the two. PMID:26536381

  1. Preparation and characterization of mucus-penetrating papain/poly(acrylic acid) nanoparticles for oral drug delivery applications

    Particle diffusion through the intestinal mucosal barrier is restricted by the viscoelastic and adhesive properties of the mucus gel layer, preventing their penetration to the underlying absorptive endothelial cells. To overcome this natural barrier, we developed nanoparticles which have a remarkable ability to cleave mucoglycoprotein substructures responsible for the structural and rheological properties of mucus. After rheological screening of various mucolytic proteases, nanoparticles composed of poly(acrylic acid) and papain were prepared and characterized regarding particle size and zeta potential. Analysis of nanoparticles showed mean diameters sub-200 nm (162.8–198.5 nm) and negative zeta potentials advancing the mobility in mucus gel. Using diffusion chamber studies and the rotating diffusion tubes method, we compared the transport rates of papain modified (PAPC) and unaltered poly(acrylic acid) (PAA) particles through freshly excised intestinal porcine mucus. Results of the diffusion assays demonstrated strongly enhanced permeation behavior of PAPC particles owing to local mucus disruption by papain. Improved transport rates, reduction in mucus viscosity and the retarded release of hydrophilic macromolecular compounds make proteolytic enzyme functionalized nanoparticles of substantial interest for improved targeted drug delivery at mucosal surfaces. Although cytotoxicity tests of the nanoparticles could not be performed, safety of papain and PAA was already verified making PAPC particles a promising candidate in the pharmaceutical field of research. The focus of the present study was the development of particles which penetrate the mucus barrier to approach the underlying epithelium. Improvements of particles that penetrate the mucus followed by cell uptake in this direction are ongoing.

  2. Poly(vinyl alcohol)/poly(acrylic acid)/TiO2/graphene oxide nanocomposite hydrogels for pH-sensitive photocatalytic degradation of organic pollutants

    Graphical abstract: The photocatalytic removal of pollutants was improved by the two-step mechanism based on the adsorption of pollutants by hydrogel and the effective decomposition by combination of TiO2 and graphene oxide. -- Highlights: • pH sensitive PVA/PAAc hydrogels were prepared by radical polymerization and condensation reaction. • PVA/PAAc/TiO2/graphene oxide nanocomposite hydrogels were used for treatment of basic waste water. • Photocatalytic acitivity of TiO2 was improved by incorporation of graphene oxide. • Photocatalytic decomposition by nanocomposite hydrogel was improved by increasing pH. -- Abstract: Poly(vinyl alcohol)/poly(acrylic acid)/TiO2/graphene oxide nanocomposite hydrogels were prepared using radical polymerization and condensation reaction for the photocatalytic treatment of waste water. Graphene oxide was used as an additive to improve the photocatalytic activity of poly(vinyl alcohol)/poly(acrylic acid)/TiO2 nanocomposite hydrogels. Both TiO2 and graphene oxide were immobilized in poly(vinyl alcohol)/poly(acrylic acid) hydrogel matrix for an easier recovery after the waste water treatment. The photocatalytic activity of poly(vinyl alcohol)/poly(acrylic acid)/TiO2/graphene oxide nanocomposite hydrogels was evaluated on the base of the degradation of pollutants by using UV spectrometer. The improved removal of pollutants was due to the two-step mechanism based on the adsorption of pollutants by nanocomposite hydrogel and the effective decomposition of pollutants by TiO2 and graphene oxide. The highest swelling of nanocomposite hydrogel was observed at pH 10 indicating that poly(vinyl alcohol)/poly(acrylic acid)/TiO2/graphene oxide nanocomposite hydrogels were suitable as a promising system for the treatment of basic waste water

  3. Poly(vinyl alcohol)/poly(acrylic acid)/TiO{sub 2}/graphene oxide nanocomposite hydrogels for pH-sensitive photocatalytic degradation of organic pollutants

    Moon, Young-E; Jung, Gowun; Yun, Jumi; Kim, Hyung-Il, E-mail: hikim@cnu.ac.kr

    2013-10-01

    Graphical abstract: The photocatalytic removal of pollutants was improved by the two-step mechanism based on the adsorption of pollutants by hydrogel and the effective decomposition by combination of TiO{sub 2} and graphene oxide. -- Highlights: • pH sensitive PVA/PAAc hydrogels were prepared by radical polymerization and condensation reaction. • PVA/PAAc/TiO{sub 2}/graphene oxide nanocomposite hydrogels were used for treatment of basic waste water. • Photocatalytic acitivity of TiO{sub 2} was improved by incorporation of graphene oxide. • Photocatalytic decomposition by nanocomposite hydrogel was improved by increasing pH. -- Abstract: Poly(vinyl alcohol)/poly(acrylic acid)/TiO{sub 2}/graphene oxide nanocomposite hydrogels were prepared using radical polymerization and condensation reaction for the photocatalytic treatment of waste water. Graphene oxide was used as an additive to improve the photocatalytic activity of poly(vinyl alcohol)/poly(acrylic acid)/TiO{sub 2} nanocomposite hydrogels. Both TiO{sub 2} and graphene oxide were immobilized in poly(vinyl alcohol)/poly(acrylic acid) hydrogel matrix for an easier recovery after the waste water treatment. The photocatalytic activity of poly(vinyl alcohol)/poly(acrylic acid)/TiO{sub 2}/graphene oxide nanocomposite hydrogels was evaluated on the base of the degradation of pollutants by using UV spectrometer. The improved removal of pollutants was due to the two-step mechanism based on the adsorption of pollutants by nanocomposite hydrogel and the effective decomposition of pollutants by TiO{sub 2} and graphene oxide. The highest swelling of nanocomposite hydrogel was observed at pH 10 indicating that poly(vinyl alcohol)/poly(acrylic acid)/TiO{sub 2}/graphene oxide nanocomposite hydrogels were suitable as a promising system for the treatment of basic waste water.

  4. Structure- Property Behavior of Poly (acrylic acid) Hydrogels Synthesized by Radiation Induced Polymerization

    Hydrogel containing hydroxyl group based on glycerol, ethylene glycol and acrylic monomer, have been prepared by using gamma radiation. The application of the prepared hydrogel for recovery of CU2+, Co2+, Ni2+, and Pb2+ was also studied. The hydrogel for complexes with metals have been isolated and characterized by using different spectroscopic techniques IR and thermal analysis. TGA thermo grams were used to determine the kinetic parameters such as activation energy and order of reaction. The complexometric titration showed that the hydrogels have a great affinity to recover the metal ions in the following order Pb2+ > Ni2+ > Cu2+ > Co2+. However the hydrogel containing glycerol has a great tendency towards metals recovery than than the one containing ethylene glycol

  5. RAFT-Mediated Polymerization-Induced Self-Assembly of Poly(Acrylic Acid-b-Poly(Hexafluorobutyl Acrylate: Effect of the pH on the Synthesis of Self-Stabilized Particles

    Jianhua Zhou

    2016-05-01

    Full Text Available This paper describes a very simple strategy towards self-stabilized poly(acrylic acid-block-poly(hexafluorobutyl acrylate (PAA-b-PHFBA block copolymer particles via reversible addition-fragmentation chain transfer (RAFT-mediated polymerization-induced self-assembly. Hexafluorobutyl acrylate (HFBA monomer conversion and number-average molar mass of PAA-b-PHFBA increased gradually with the increase in the pH value of the aqueous phase. When pH < 10, the molecular weight distributions of PAA-b-PHFBA were narrow, however, when the pH was raised to 11.55, PAA-b-PHFBA block copolymers had a broader distribution (ĐM = 1.82 with a serious trailing toward the low molecular weight. Furthermore, the morphology and size of PAA-b-PHFBA latex particles were measured by transmission electron microscopy and dynamic light scattering. The results indicated that the PAA-b-PHFBA latex particles had a clear spherical core-shell structure and the latex particles’ size increased with the increase of pH value.

  6. In vitro release studies of vitamin B12 from poly N-vinyl pyrrolidone /starch hydrogels grafted with acrylic acid synthesized by gamma radiation

    Co-polymeric hydrogels containing N-vinyl pyrrolidone and starch grafted with acrylic acid were synthesized by gamma radiation. Their gel contents, grafting process and swelling were evaluated. The gels were also characterized by thermal gravimetric analysis. The gel content found to be increase with increasing the irradiation dose up to 50 kGy then decrease. The grafting percent increase by increasing the percentage of acrylic acid in the grafted hydrogels. The thermal stability and the rate of the thermal decomposition showed to be changed according to the different composition of the hydrogels. It also showed a decrease in the maximum rate of the thermal decomposition by the increasing of the irradiation dose from 20 to 30 kGy and increases by increasing the irradiation dose from 30 to 70 kGy. The hydrogels loaded with vitamin B12 as drug model, demonstrated a decrease release in acidic medium than the neutral one

  7. Radiation Synthesis of Stimuli-Responsive Hydrogels and Their Interactions with Poly(acrylic acid) and Ionic Surfactants

    those with high content of hydrophobic moiety. Considerable improvement of thermo-induced collapse behavior, namely high amplitude and narrower temperature interval of collapse was shown for the certain sample. In the present work also novel pH-responsive hydrogels of cationic and amphoteric nature were synthesized by gamma-radiation copolymerization of vinyl ethers of monoethanolamine (VEMEA) and ethyleneglycol (VEEG) as well as VEMEA and acrylic acid (AA). The synthesis regularities have been studied. The effects of the feed mixture, cross-linker concentration, absorbed dose on the gel/sol fractions and swelling behavior of the hydrogels is studied. The swelling behavior of the hydrogels was studied as a function of pH. It was found that the isoelectric point of the polyampholyte hydrogels based on VEMEA and AA depends on the composition of copolymers. The interactions of the amphoteric hydrogels based on VEMEA and AA with linear poly(acrylic acid) and poly(vinyl ether of monoethanolamine) lead to the formation of gel-polymer interpolyelectrolyte compexes. It was demonstrated that the cationic hydrogels VEMEA-VEEG are able to bind poly(acrylic acid) to form polyelectrolyte complexes with swelling properties typical for polyampholytes

  8. Chemical crosslinking of acrylic acid to form biocompatible pH sensitive hydrogel reinforced with cellulose nanocrystals (CNC)

    Lim, Lim Sze; Ahmad, Ishak; Lazim, Mohd Azwani Shah Mat [Faculty of Science and Technology, University Kebangsaan Malaysia, 43600 UKM, Bangi, Selangor (Malaysia); Amin, Mohd. Cairul Iqbal Mohd [Faculty of Pharmacy, University Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur (Malaysia)

    2014-09-03

    The purpose of this study is to produce a novel pH and temperature sensitive hydrogel, composed of poly(acrylic acid) (PAA) and cellulose nanocrystal (CNC). CNC was extracted from kenaf fiber through a series of alkali and bleaching treatments followed by acid hydrolysis. The PAA was then subjected to chemical cross-linking using the cross-linking agent (N,N-methylenebisacrylamide) with CNC entrapped in PAA matrix. The mixture was casted onto petri dish to obtain disc shape hydrogel. The effects of reaction conditions such as the ratio of PAA and CNC on the swelling behavior of the hydrogel obtained towards pH and temperature were studied. The obtained hydrogel was further subjected to different tests such swelling test for swelling behaviour at different pH and temperature along with scanning electron microscopy (SEM) for morphology analysis. The hydrogel obtained showed excellent pH sensitivity and obtained maximum swelling at pH 7. Besides that, hydrogel obtained showed significant increase in swelling ratio when temperature of swelling medium was increased from 25°C to 37°C. SEM micrograph showed that the pore size of the hydrogel decreases with increase of CNC content proving that the hydrogel structure became more rigid with addition of CNC. The PAA/CNC hydrogel with such excellent sensitivity towards pH and temperature can be developed further as drug carrier.

  9. Chemical crosslinking of acrylic acid to form biocompatible pH sensitive hydrogel reinforced with cellulose nanocrystals (CNC)

    Lim, Lim Sze; Ahmad, Ishak; Lazim, Mohd Azwani Shah Mat; Amin, Mohd. Cairul Iqbal Mohd

    2014-09-01

    The purpose of this study is to produce a novel pH and temperature sensitive hydrogel, composed of poly(acrylic acid) (PAA) and cellulose nanocrystal (CNC). CNC was extracted from kenaf fiber through a series of alkali and bleaching treatments followed by acid hydrolysis. The PAA was then subjected to chemical cross-linking using the cross-linking agent (N,N-methylenebisacrylamide) with CNC entrapped in PAA matrix. The mixture was casted onto petri dish to obtain disc shape hydrogel. The effects of reaction conditions such as the ratio of PAA and CNC on the swelling behavior of the hydrogel obtained towards pH and temperature were studied. The obtained hydrogel was further subjected to different tests such swelling test for swelling behaviour at different pH and temperature along with scanning electron microscopy (SEM) for morphology analysis. The hydrogel obtained showed excellent pH sensitivity and obtained maximum swelling at pH 7. Besides that, hydrogel obtained showed significant increase in swelling ratio when temperature of swelling medium was increased from 25°C to 37°C. SEM micrograph showed that the pore size of the hydrogel decreases with increase of CNC content proving that the hydrogel structure became more rigid with addition of CNC. The PAA/CNC hydrogel with such excellent sensitivity towards pH and temperature can be developed further as drug carrier.

  10. Chemical crosslinking of acrylic acid to form biocompatible pH sensitive hydrogel reinforced with cellulose nanocrystals (CNC)

    The purpose of this study is to produce a novel pH and temperature sensitive hydrogel, composed of poly(acrylic acid) (PAA) and cellulose nanocrystal (CNC). CNC was extracted from kenaf fiber through a series of alkali and bleaching treatments followed by acid hydrolysis. The PAA was then subjected to chemical cross-linking using the cross-linking agent (N,N-methylenebisacrylamide) with CNC entrapped in PAA matrix. The mixture was casted onto petri dish to obtain disc shape hydrogel. The effects of reaction conditions such as the ratio of PAA and CNC on the swelling behavior of the hydrogel obtained towards pH and temperature were studied. The obtained hydrogel was further subjected to different tests such swelling test for swelling behaviour at different pH and temperature along with scanning electron microscopy (SEM) for morphology analysis. The hydrogel obtained showed excellent pH sensitivity and obtained maximum swelling at pH 7. Besides that, hydrogel obtained showed significant increase in swelling ratio when temperature of swelling medium was increased from 25°C to 37°C. SEM micrograph showed that the pore size of the hydrogel decreases with increase of CNC content proving that the hydrogel structure became more rigid with addition of CNC. The PAA/CNC hydrogel with such excellent sensitivity towards pH and temperature can be developed further as drug carrier

  11. Vinyl ether/acrylic acid terpolymer hydrogels synthesized by γ-radiation: characterization, thermosensitivity and pH-sensitivity

    The radiation copolymerization of hydrophilic ethylene glycol vinyl ether (EGVE), hydrophobic butyl vinyl ether (BVE) and/or acidic comonomer acrylic acid (AA) was realized in the presence of crosslinking agent diethylene glycol divinyl ether (DEGDVE). The swelling studies which were carried out at 4 and 37 deg. C in phosphate buffer solution (PBS, pH 7.4) showed that equilibrium swelling ratios of the hydrogels (except EGVE homopolymer hydrogel) decreases with increasing temperature and swelling process obeys non-Fickian diffusion mechanism. The pH-dependent swelling behaviour of the hydrogels was examined in buffered solutions at various pHs. The swelling process is reversible and pH-dependent for the AA-containing hydrogel. While this hydrogel shows a fully hydrated form at pH>6; it extensively dehydrates below pH 6. The gels are stable after the repeated swelling experiments. The molecular structure of the hydrogels was studied by Fourier Transform Infrared Spectroscopy and their thermal behaviour was investigated by Differential Scanning Calorimetry and Thermal Gravimetric Analysis. The surface and cross-section structures of the gels were examined by a Scanning Electron Microscope

  12. Optimal Design for Reactivity Ratio Estimation: A Comparison of Techniques for AMPS/Acrylamide and AMPS/Acrylic Acid Copolymerizations

    Alison J. Scott

    2015-11-01

    Full Text Available Water-soluble polymers of acrylamide (AAm and acrylic acid (AAc have significant potential in enhanced oil recovery, as well as in other specialty applications. To improve the shear strength of the polymer, a third comonomer, 2-acrylamido-2-methylpropane sulfonic acid (AMPS, can be added to the pre-polymerization mixture. Copolymerization kinetics of AAm/AAc are well studied, but little is known about the other comonomer pairs (AMPS/AAm and AMPS/AAc. Hence, reactivity ratios for AMPS/AAm and AMPS/AAc copolymerization must be established first. A key aspect in the estimation of reliable reactivity ratios is design of experiments, which minimizes the number of experiments and provides increased information content (resulting in more precise parameter estimates. However, design of experiments is hardly ever used during copolymerization parameter estimation schemes. In the current work, copolymerization experiments for both AMPS/AAm and AMPS/AAc are designed using two optimal techniques (Tidwell-Mortimer and the error-in-variables-model (EVM. From these optimally designed experiments, accurate reactivity ratio estimates are determined for AMPS/AAm (rAMPS = 0.18, rAAm = 0.85 and AMPS/AAc (rAMPS = 0.19, rAAc = 0.86.

  13. Mechanism of poly(acrylic acid) acceleration of antithrombin inhibition of thrombin: implications for the design of novel heparin mimics.

    Monien, Bernhard H; Cheang, Kai I; Desai, Umesh R

    2005-08-11

    The bridging mechanism of antithrombin inhibition of thrombin is a dominant mechanism contributing a massive approximately 2500-fold acceleration in the reaction rate and is also a key reason for the clinical usage of heparin. Our recent study of the antithrombin-activating properties of a carboxylic acid-based polymer, poly(acrylic acid) (PAA), demonstrated a surprisingly high acceleration in thrombin inhibition (Monien, B. H.; Desai, U. R. J. Med. Chem. 2005, 48, 1269). To better understand this interesting phenomenon, we have studied the mechanism of PAA-dependent acceleration in antithrombin inhibition of thrombin. Competitive binding studies with low-affinity heparin and a heparin tetrasaccharide suggest that PAA binds antithrombin in both the pentasaccharide- and the extended heparin-binding sites, and these results are corroborated by molecular modeling. The salt-dependence of the K(D) of the PAA-antithrombin interaction shows the formation of five ionic interactions. In contrast, the contribution of nonionic forces is miniscule, resulting in an interaction that is significantly weaker than that observed for heparins. A bell-shaped profile of the observed rate constant for antithrombin inhibition of thrombin as a function of PAA concentration was observed, suggesting that inhibition proceeds through the "bridging" mechanism. The knowledge gained in this mechanistic study highlights important rules for the rational design of orally available heparin mimics. PMID:16078853

  14. Preparation of Quarternized Acrylic Acid Grafted Cotton Fabric Waste for the Removal of Sulphate from Aqueous Solution

    Acrylic acid (AAc) grafted cotton fabric was prepared by radiation- induced graft polymerization. Grafting conditions were optimized and the sample with grafting percentage 160% were used for further experiments. (AAc) grafted chains were quaternized by introduction of a tertiary amine function onto the sample by the estrification of the carboxylic groups, via an acid chloride intermediate, with 4-hydroxy-N-methyl piperidine. The tertiary amine of the piperidine ring was then quarternized with benzyl chloride. The prepared anion exchanger was characterized by FTIR and SEM. Adsorption experiments were conducted with quarternized (AAc) grafted cotton fabric for sulphate removal at concentration (100-500 ppm) at different ph values. Adsorbed sulphate amounts were found to be (60, 32.5 and 22.5 mg/g) at ph 3, 7 and 9, respectively, showing the efficiency of the adsorbent material in the removing sulphate. Also the results showed that the adsorption data fit the Freundlich isotherm model. Kinetic data were fitted using pseudo-first-order, pseudo-second order equations and with the pseudo-second-order equation generated being in best agreement with the experimental data for the adsorption systems

  15. Diffusion coefficient, porosity measurement, dynamic and equilibrium swelling studies of Acrylic acid/Polyvinyl alcohol (AA/PVA hydrogels

    Nazar Mohammad Ranjha

    2015-06-01

    Full Text Available Objective of the present work was to synthesize hydrogels of acrylic acid/polyvinyl alcohol (AA/PVA by free radical polymerization by using glutaradehyde (GA as crosslinkers. The hydrogels were evaluated for swelling, diffusion coefficient and network parameters like the average molecular weight between crosslink’s, polymer volume fraction in swollen state, number of repeating units between crosslinks and crosslinking density by using Flory-Huggins theory. It was found that the degree of swelling of AA/PVA hydrogels increases greatly within the pH range 5-7. The gel fraction and porosity increased by increasing the concentration of AA or PVA. Increase in degree of crosslinking, decreased the porosity and inverse was observed in gel fraction. Selected samples were loaded with metoprolol tartrate. Drug release was studied in USP hydrochloric acid solution of pH 1.2 and phosphate buffer solutions of pH 5.5 and 7.5. Various kinetics models like zero order, first order, Higuchi and Peppas model were used for in vitro kinetic studies. The results showed that the drug release followed concentration dependent effect (First order kinetics with non-Fickian diffusion. FTIR and SEM used to study the structure, crystallinity, compatibility, thermal stability and morphology of prepared and drug loaded hydrogels respectively.

  16. Modification of Oxidized Paraffin Wax Grafted by Acrylic Acid%氧化蜡接枝丙烯酸的改性研究

    陈鹏; 纪灵娴; 王德; 丛玉凤; 黄玮

    2013-01-01

    Melted oxidized paraffin wax grafted by acrylic acid was studied in this paper ,it was discussed respectively about factors influencing grafted rate of melted oxidized paraffin wax , like reaction temperature , the dosage of ammonium persulphate ,the dosage of acrylic acid and reaction time etc .It was ascertained that the proper conditions of orthogonal technology of melted oxidized paraffin wax grafted by acrylic acid ,reaction temperature was 85 ℃ ,the dosage of ammonium persulphate 3 .5% ~ 4 .5% , the dosage of acrylic acid 40% , reaction time 3 h .Finally , according to optimum proposal summarized by orthogonal experiment ,modified oxidized paraffin wax was prepared with great characters of acid value ,grafted rate ,storage and centrifuge stability etc .%对丙烯酸接枝熔融氧化蜡进行了研究,分别探讨了反应温度、过硫酸铵质量分数、丙烯酸质量分数、反应时间等因素对熔融氧化蜡的接枝率的影响,确定了合适的丙烯酸接枝熔融氧化蜡的正交工艺条件为:反应温度为85℃,过硫酸铵质量分数为3.5%~4.5%,丙烯酸质量分数为40%,反应时间为3h,最终按照正交实验总结出的优化方案制备出了接枝率、酸值、贮存与离心稳定性等性质优异的改性氧化蜡。

  17. Storage Stability Improvement of Copolymer Grafted Polypropylene-AcrylicAcid (PP-AA), by means of Various After Treatment Processes

    Polypropylene yams that have been subjected to irradiation induced graftco-polymerization with acrylic acid, have gained its moisture regain and dyeability, that fulfilled the requirement as textile material for garment.However, the copolymer grafted PP-AA has suffered from degradation in thestorage, which was indicated in the previous study that the strengthretention has dropped tremendously by photo-oxidation or photo-degradation.After treatments of PP-AA yams with chemical compound that was able toprevent further photo-oxidation, will be expected to improve the stability ofPP-AA in storage. In this research activity, the polypropylene (PP) yams weresubjected to irradiation induced graft co-polymerization by means ofγ-Ray Co-60 as irradiation source with acrylic acid (AA) as monomer.Various after treatments were subjected to the grafted PP-AA yams such asalkalisation process; dyeing (anionic dyes, cationic dyes and nonionic dyes);as well as processing with optical brightening agent and UV stabilizer,separately. The PP-AA yams (before and after treatment) were subjected tostorage from 1 month up to 42 months, and then being tested for theirmoisture regain, strength retention and elongation at breaks. The samplesbeing stored for 12 months were subjected to radical analysis. It isconcluded from the experiment that after treatment of grafted PP-AA by meansof those various processes were able to improve the stability of copolymergrafted PP-AA in storage. The presence of peroxide radical in the ESR(electron spin resonance) spectrum on PP-AA yams before treatment and theones after treated with alkaline and being stored for 12 months haveindicated the presence of photo oxidation or photo degradation, while thepresence of poly enyl radical in the ESR spectrum of after treated PP-AA withdyes having azo and azine compound as chromophore, as well as with UVstabilizer with carbonyl as chromophore and being stored for 12 months haveproved that its presence have protected such

  18. The effect of extended polymer chains on the properties of transparent multi-walled carbon nanotubes/poly(methyl methacrylate/acrylic acid) film

    Huang, Yuan-Li; Tien, Hsi-Wen; Ma, Chen-Chi M; Yu, Yi-Hsiuan; Yang, Shin-Yi; Wu, Sheng-Yen [Department of Chemical Engineering, National Tsing-Hua University, Hsin-Chu 30043, Taiwan (China); Wei, Ming-Hsiung, E-mail: ccma@che.nthu.edu.tw [Chemical Systems Research Division, Chung Shan Institute of Science and Technology, Tao Yuan 32546, Taiwan (China)

    2010-05-07

    Optically transparent and electrically conductive thin films composed of multi-walled carbon nanotube (MWCNT) reinforced polymethyl methacrylate/acrylic acid (PMMA/AA) were fabricated using a wire coating technique. Poly(acrylic acid) controls the level of MWCNT dispersion in aqueous mixtures and retains the well-dispersed state in the polymer matrix after solidification resulting from extended polymer chains by adjusting the pH value. The exfoliating the MWCNT bundles by extended polymer chains results in the excellent dispersion of MWCNT. It causes a lower surface electrical resistance at the same MWCNT content. The hydrophilic functional groups (-COO{sup -}NA{sup +}) also caused a decrease in the crystallization of PMMA and led to an increase in the transmittance.

  19. Characterization and Absorbing Properties of Oil Palm Empty Fruit Bunch Filled Poly (Acrylic Acid-co-Acrylamide) Super absorbent Polymer Composites

    Oil palm empty fruit bunch graft poly (acrylic acid-co-acrylamide) super absorbent composite (OPEFB-g-(PAA-co-PAM) SAPC) was synthesized by graft copolymerization of the acrylic acid (AA) and acrylamide (AM) comonomer onto OPEFB fibre using ammonium persulfate (APS) and N,N-methylene bisacarylamide (MBA) as an initiator and crosslinked, respectively. The absorbency in various chloride salt solutions indicated that the absorbency decreased with increasing ionic strength of the salt solutions. Moreover, the absorbency under load (AUL) of SAPC was investigated at various applied loading and results show that, AUL decreased with increasing applied loading. Infrared Spectroscopy (IR) and Thermogravimetric Analysis (TGA) were carried out to confirm the chemical structure and thermal properties of the synthesized super absorbent, respectively. (author)

  20. The effect of distribution of monomer moiety on the pH response and mechanical properties of poly(acrylonitrile-co-acrylic acid) copolymers

    The pH response and mechanical properties of copolymer-based hydrogels such as poly(acrylonitrile-co-acrylic acid) are usually attributed to their chemical composition. In this study, it has been shown that the architecture of the polymer chains, i.e. the distribution of comonomers in the macromolecules, also plays a major role in controlling these properties. A series of four poly(acrylonitrile-co-acrylic acids) with fixed composition (i.e. ∼30 mol% acrylic acid moieties) were synthesized, where the block lengths of both AN (acrylonitrile) and AAc (acrylic acid) moieties in the copolymers were varied by controlling the feeding pattern of the monomers during free radical copolymerization. These copolymers were then converted into fine fibers of the same dimensions. The monomer distribution in the four copolymers was estimated using quantitative carbon 13C nuclear magnetic resonance (NMR) and related to the mechanical and pH response properties of the resultant fibers. The pH response of the fibers with similar composition increased dramatically as the block length of the AAc moiety was increased, while the mechanical properties increased as a direct function of the block length of the AN moieties. The fiber's response at pH 10 in terms of the change in length increased by ∼four times while its response rate increased by ∼50 times with the increase in block length of the AAc moiety. On the other hand, the tensile properties and retractive stress increased by ∼four times with the increase in the block length of the AN moiety

  1. Synthesis of Graft Copolymer of Sodium Humate-Acrylic Acid%腐植酸钠-丙烯酸接枝共聚物的合成研究

    张荣明; 生金峰; 李鹏; 程焱召

    2011-01-01

    Grafting copolymerization of sodium humate with acrylic acid initiated by potassium persulfate was studied by aqueous solution polymerization method. The influential factors, such as reaction temperature, reaction time, initiator rate, the neutralization degree of acrylic acid and the reactant mass ratio were explored. The results showed that the optimum condition was 90% neutralization degree of acrylic acid, 50:1 (g/g) of acrylic acid to sodium humate, 4.0% initiator in reactant (compared with AA), and 60℃ for 8h. The structure of product was characterizedby IR.%采用水溶液聚合方法,以过硫酸钾为引发剂,腐植酸、丙烯酸为原料接枝共聚。考察了丙烯酸中和度、引发剂用量、物料比、反应温度和反应时间等因素对合成腐植酸钠-丙烯酸接枝共聚物的影响。结果表明,最佳聚合工艺条件为:丙烯酸中和度90%,反应温度60℃,反应时间8h,加入引发剂浓度为4.0%(AA单体为参照),丙烯酸与腐植酸钠物料比为50:1(g/g),通过红外光谱对聚合物的结构进行了表征。

  2. Capture of Tumor Cells on Anti-EpCAM-Functionalized Poly(acrylic acid)-Coated Surfaces.

    Andree, Kiki C; Barradas, Ana M C; Nguyen, Ai T; Mentink, Anouk; Stojanovic, Ivan; Baggerman, Jacob; van Dalum, Joost; van Rijn, Cees J M; Terstappen, Leon W M M

    2016-06-15

    The presence of tumor cells in blood is predictive of short survival in several cancers and their isolation and characterization can guide toward the use of more effective treatments. These circulating tumor cells (CTC) are, however, extremely rare and require a technology that is sufficiently sensitive and specific to identify CTC against a background of billions of blood cells. Immuno-capture of cells expressing the epithelial cell adhesion molecule (EpCAM) are frequently used to enrich CTC from blood. The choice of bio conjugation strategy and antibody clone is crucial for adequate cell capture but is poorly understood. In this study, we determined the binding affinity constants and epitope binding of the EpCAM antibodies VU1D-9, HO-3, EpAb3-5, and MJ-37 by surface plasmon resonance imaging (SPRi). Glass surfaces were coated using a poly(acrylic acid) based coating and functionalized with anti-EpCAM antibodies. Binding of cells from the breast carcinoma cell line (SKBR-3) to the functionalized surfaces were compared. Although EpAb3-5 displayed the highest binding affinity HO-3 captured the highest amount of cells. Hence we report differences in the performance of the different antibodies and more importantly that the choice of antibody to capture CTC should be based on multiple assays. PMID:27187784

  3. Radiation synthesis and characterization of pH-sensitive poly(acrylic acid-co-N-vinyl-2-pyrrolidone) hydrogels

    Hydrogels are crosslinked, three-dimensional hydrophilic polymer networks that swell but do not dissolve when brought into contact with water. These materials have been investigated extensively for potential applications in the biomedical field because of their similarities to soft tissues and their good tissue and blood compatibility. More specifically, pH-sensitive hydrogels are used for sustained gastro-intestinal drug delivery systems due to the intimacy and extended duration of contact. In this work, pH-sensitive copolymer hydrogels were prepared using acrylic acid and N-vinyl-2-pyrrolidone by γ-ray irradiation at ambient temperature. Effects of dose, monomer concentration, monomer composition, temperature and pH on the swelling ratio (SR) of the copolymer hydrogels were investigated in detail. The results show that SR of the copolymer hydrogels decreases with the monomer concentration and with the increase of absorbed dose. These copolymer hydrogels show good pH-sensitive behavior. These material shows no noticeable change in swelling at lower pH (pH<4) but an abrupt increase in swelling at higher pH (from pH7 to pH9.8). At pH 1.4, the SR of the copolymer hydrogels increases with the temperature. To the contrary, at pH 9.8, the SR of the copolymer hydrogels decreases with the temperature. (authors)

  4. Radiation preparation and characterization of pH-sensitive hydrogel of acrylic acid/cyclodextrin based copolymer

    A β-cyclodextrin (β-CD) based monomer (MAH-β-CD) containing vinyl and carboxyl functional groups was synthesized by reaction of β-CD with maleic anhydride (MAH). A novel hydrogel, poly(AAc-co-MAH-β-CD) with pH and ionic strength sensitivities, was prepared by irradiating the aqueous solution mixture of acrylic acid (AAc) and MAH-β-CD with electron beam. The effect of the feed ratio of the components and irradiation dose on the swelling and deswelling properties of the hydrogel was studied, respectively, the effect of pH and ionic strength on the swelling ratio was determined. Experimental results showed that these copolymer hydrogels did not show any noticeable change in swelling ratio at lower pH range (pH 1-3). However they showed an abrupt increase in swelling ratio at the range of pH 3-6, due to the ionization of carboxyl groups. Fourier transform infrared (FT-IR) spectrometer was applied in the attenuated total reflectance (ATR) mode for analyzing the structure change of the hydrogels after the treatment of different pH buffer solutions. (author)

  5. Structure formation of soil dispersions in the presence of polyelectrolytes on the basis of allyl alcohol and acryl acid derivatives

    Amankait Asanov

    2015-09-01

    Full Text Available Some changes of structural composition and surface properties of soil dispersions in the presence of polyelectrolytes, based on allyl alcohol and acryl acid derivatives, have been studied. The results show, that the changes in the structure of soil dispersions composition are connected with the added concentration and pH value, that depend on mole ratio and nature of functional groups, as well as on the nature of counterions and concomitant electrolytes, changing with the conditions of polymer analogous conversion and neutralization reaction. Experimental data show, that the change in the conformational state and the length of the macromolecule has a significant impact on the structure-forming effect and the amount of polyelectrolyte, needed to achieve the same degree of structure-forming effect of soil dispersions. The causes for the revealed reasons are shown on the basis of the results of the experiment. Along with this, it was found that particular changes of structural composition and surface properties of the soil dispersions depend on the type and concentration of the added polyelectrolyte.

  6. Response of Swelling Behavior of Weak Branched Poly(ethylene imine)/Poly(acrylic acid) Polyelectrolyte Multilayers to Thermal Treatment.

    Gu, Yuanqing; Weinheimer, Emily K; Ji, Xiang; Wiener, Clinton G; Zacharia, Nicole S

    2016-06-21

    Weak polyelectrolyte multilayers (PEMs) prepared by the layer-by-layer technique have attracted a great deal of attention as smart responsive materials for biological and other applications in aqueous medium, but their dynamic behavior as a function of exposure to a wide temperature range is still not well understood. In this work, the thermally dependent swelling behavior of PEMs consisting of branched poly(ethylenimine) and poly(acrylic acid) is studied by temperature controlled in situ spectroscopic ellipsometry. Because of diffusion and interpenetration of polyelectrolytes during film deposition, the PEMs densify with increasing bilayer number, which further affects their water uptake behavior. Upon heating to temperatures below 60 °C, the worsened solvent quality of the PEM in water causes deswelling of the PEMs. However, once heated above this critical temperature, the hydrogen bonds within the PEMs are weakened, which allows for chain rearrangement within the film upon cooling, resulting in enhanced water uptake and increased film thickness. The current work provides fundamental insight into the unique dynamic behavior of weak polyelectrolyte multilayers in water at elevated temperatures. PMID:27232180

  7. Preparation of thermosensitive membranes by radiation grafting of acrylic acid/ N-isopropyl acrylamide binary mixture on PET fabric

    Gupta, Bhuvanesh; Mishra, Swaiti; Saxena, Shalini

    2008-05-01

    Thermosensitive membranes were prepared by radiation-induced graft copolymerization of monomers on PET fabrics. A binary mixture of N-isopropyl acrylamide (NIPAAm) and acrylic acid (AA) was grafted on polyester fabric as a base material to introduce thermosensitive poly( N-isopropyl acrylamide) pendant chains having LCST slightly higher than 37 °C in the membrane. The influence of ferrous sulfate, radiation dose and monomer composition on the degree of grafting was studied. The structure of the grafted fabric was characterized by thermogravimetric analysis, differential scanning calorimetry and scanning electron microscopy. The thermosensitive nature of the fabric was monitored by swelling at different temperatures. The graft copolymerization of AA with NIPAAm enhanced the LCST of the resultant membrane to ˜37 °C. The moisture vapor transmission rate (MVTR) and air permeability of the fabric decreased slightly, may be due to the slight blocking of the fabric pores. The immobilization of tetracycline hydrochloride as the model drug and its release characteristics at different temperatures were monitored.

  8. STUDY OF COMPOSITE MEMBRANE OF CELLULOSE ACETATE OR POLYVINYL ALCOHOL BLENDED WITH METHYLMETHACRYLATE-ACRYLIC ACID COPOLYMER FOR PERVAPORATION SEPARATION

    Huan-lin Chen; Jun Tan; Mo-e Liu; Chang-luo Zhu

    1999-01-01

    In this paper, methylmethacrylate-acrylic acid MMA-AA hydrophilic and hydrophobic copolymers were prepared by copolymerization for preparing membrane materials. The composite membrane of cellulose acetate (CA) blended with MMA-AA hydrophobic copolymer was used for the separation of methanol from pentane-methanol mixture. When the methanol concentration was only 1 wt%, the permeate flux still maintained at 350 g/m2h and separation factor was as big as 800. The composite membrane of PVA (polyvinyl alcohol) blended with MMA-AA hydrophilic copolymer was used for the separation of ethanolwater mixture. The permeate flux was increased to 975 g/m2h at 74℃ and the separation factor reached 3000at 25℃. The PVA/MMA-AA blended membrane surface modified by ammonia plasma was also investigated for separating ethanol-water mixture. Both permeate flux and separation factor of the membrane was improved. However, there was no obvious difference of plasma treatment time in the interval of 20~40 min.

  9. Highly hydrophilic ultra-high molecular weight polyethylene powder and film prepared by radiation grafting of acrylic acid

    Wang, Honglong.; Xu, Lu.; Li, Rong.; Pang, Lijuan.; Hu, Jiangtao.; Wang, Mouhua.; Wu, Guozhong.

    2016-09-01

    The surface properties of ultra-high molecular weight polyethylene (UHMWPE) are very important for its use in engineering or composites. In this work, hydrophilic UHMWPE powder and film were prepared by γ-ray pre-irradiation grafting of acrylic acid (AA) and further neutralization with sodium hydroxide solution. Variations in the chemical structure, grafting yield and hydrophilicity were investigated and compared. FT-IR and XPS analysis results showed that AA was successfully grafted onto UHMWPE powder and film; the powder was more suitable for the grafting reaction in 1 wt% AA solution than the film. Given a dose of 300 kGy, the grafting yield of AA was ∼5.7% for the powder but ∼0.8% for the film under identical conditions. Radiation grafting of a small amount of AA significantly improved the hydrophilicity of UHMWPE. The water contact angle of the UHMWPE-g-PAA powder with a grafting yield of AA at ∼5.7% decreased from 110.2° to 68.2°. Moreover, the grafting powder (UHMWPE-g-PAA) exhibited good dispersion ability in water.

  10. Synthesis of silica coated zinc oxide–poly(ethylene-co-acrylic acid) matrix and its UV shielding evaluation

    Graphical abstract: - Highlights: • Well layer thickness controlled silica shell was made on ZnO nanoparticles. • PEAA, an interfacial agent is used to make nanocomposite–polymer matrix by twin-screw extruder. • Si-ZnO/PEAA matrix is highly stable and UV protective as compared to ZnO/PEAA matrix. • Nanoparticle embedded polymer matrix is suggested to make UV shielding fabrics with Nylon4. - Abstract: Silica coated zinc oxide nanoparticles (Si-ZnO NPs) (7 nm thick) were synthesized successfully and melt blended with poly(ethylene-co-acrylic acid) (PEAA resin) to improving ultraviolet (UV) shielding of zinc oxide nanoparticles (ZnO NPs). The photostability of both the ZnO NPs and Si-ZnO NPs were analyzed by the difference in photoluminescence (PL) and by methylene blue (MB) degradation. Photo-degradation studies confirmed that Si-ZnO NPs are highly photostable compared to ZnO NPs. The melt blended matrices were characterized by field emission scanning electron microscopy interfaced with energy dispersive X-ray spectroscopy (FE-SEM-EDX). The UV shielding property was analyzed from the transmittance spectra of UV–visible (UV–vis) spectroscopy. The results confirmed fine dispersion of thick Si-ZnO NPs in the entire resin matrix. Moreover, the Si-ZnO/PEAA showed about 97% UV shielding properties than the ZnO/PEAA

  11. Study of iron (III) complexed with radiation grafted acrylic acid onto poly (tetrafluoroethylene-Co-perfluoro vinyl ether) films

    To introduce functional moieties to a poly (tetrafluoroethylene-Co-perfluoro vinyl ether) film (PFA) graft copolymerization of vinyl monomer such as acrylic acid (AAc) was attempted by a simultaneous technique in aqueous solution using γ-irradiation. The graft copolymer was complexed with the Fe (III) in aqueous solution. The grafted copolymer-metal complexes were examined by infrared (IR), ultraviolet (UV), energy-dispersive X-ray (EDX) and electron spin resonance (ESR) techniques. The effect of temperature on the trunk copolymer, untreated grafted and treated grafted copolymer films was examined by IR and thermogravimetric analysis (TGA). The overall results suggest octahedral environment for Fe (III) and revealed the high ability of the obtained ligand-metal complexes. Furthermore, scanning electron microscope (SEM) investigation of the grafted and modified films, both unheated and heated (200 degree C) showed changes in the structure and surface morphology. It was found that the modified grafted membranes may make them promising for some practical applications such as the recovery of metal from aqueous systems

  12. Enhancing antibiofouling performance of Polysulfone (PSf) membrane by photo-grafting of capsaicin derivative and acrylic acid

    Wang, Jian; Sun, Haijing; Gao, Xueli; Gao, Congjie

    2014-10-01

    Biofouling is a critical issue in membrane water and wastewater treatment. Herein, antibiofouling PSf membrane was prepared by UV-assisted graft polymerization of acrylic acid (AA) and a capsaicin derivative, N-(5-methyl-3-tert-butyl-2-hydroxy benzyl) acrylamide (MBHBA), on PSf membrane. AA and MBHBA were used as hydrophilic monomer and antibacterial monomer separately. The membranes were characterized by FTIR-ATR, contact angle, SEM, AFM, cross-flow filtration unit, antifouling and antibacterial measurements. Verification of MBHBA and AA that photo-chemically grafted onto the PSf membrane surface is confirmed by carbonyl stretching vibration at ∼1655 cm-1 and ∼1730 cm-1, separately. The increasing AA concentration accelerates the graft-polymerization of MBHBA and resulted in a more hydrophilic surface. Consequently, antifouling property of the membranes was improved on a large level. The flux recovery rate can achieve 100% during the cyclic test, which may be attributed to the more hydrophilic and smooth surface, as well as the decreased membrane pore size. Most importantly, the presence of AA in graft co-polymer does not affect the antibacterial activity of MBHBA. That may be induced by the increasing chain length and flexibility of the grafted polymer chains.

  13. Removal of reactive dyes from textile wastewater by immobilized chitosan upon grafted Jute fibers with acrylic acid by gamma irradiation

    Jute fibers were grafted with acrylic acid by gamma irradiation technique. Chitosan was immobilized upon the grafted Jute fibers to be used as an adsorbent for waste reactive dye. The treated Jute fibers were characterized by using of Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and X-ray diffraction (XRD). The effect of Jute treatment on its thermal stability by using thermogravimetric analysis (TGA) and its mechanical properties were investigated. The adsorption isotherm and the different factors affecting the dye adsorption such as pH and contact time were also studied. It was found that the dye adsorption was enhanced in the low pH range and increased with increasing of the contact time, regardless of temperature change. - Highlights: • Jute fibers were grafted by PAAc followed by immobilization with chitosan. • The treated Jute fibers were used as dye adsorbent from wastewater. • The different factors which affect the adsorption process were studied. • The higher adsorption capacity was achieved at low pH. • The treated Jute fibers can be used for three times after regeneration processes

  14. A drug-loaded gel based on polyelectrolyte complexes of poly (acrylic acid) with poly (vinylpyrrolidone) and chitosan

    A drug-loaded gel (CSPP) based on ionic crosslinked chitosan (CS) and polyelectrolyte complexes of poly (acrylic acid) (PAA) with poly (vinylpyrrolidone) (PVP) was prepared by dropping CS solution containing suitable amount of PVP into PAA and trisodium citrate co-existing gelling solution. The surface and cross-section morphology of the gel was observed using scanning electron microscopy, and the observation showed that the CSPP gel had more compact structure than CS gel. In vitro release profiles of model drug from the CSPP gel, which was prepared under different conditions, were investigated in simulative gastric fluid (pH 1.8) using an UV/vis spectrophotometer. The results showed that the rapid release of the model was restrained due to the complex of PVP and PAA, and the CSPP gel could serve as a suitable candidate in drug delivery system such as the site-specific controlled release of the drug in stomach. In addition, the release mechanism of drug was analyzed by fitting the amount of drug released into Peppa's potential equation.

  15. Experimental Study and Numerical Solution of Poly Acrylic Acid Supported Magnetite Nanoparticles Transport in a One-Dimensional Porous Media

    M. Golzar

    2014-01-01

    Full Text Available Recently, iron nanoparticles have attracted more attention for groundwater remediation due to its potential to reduce subsurface contaminants such as PCBs, chlorinated solvents, and heavy metals. The magnetic properties of iron nanoparticles cause to attach to each other and form bigger colloid particles of iron nanoparticles with more rapid sedimentation rate in aqueous environment. Using the surfactants such as poly acrylic acid (PAA prevents iron nanoparticles from forming large flocs that may cause sedimentation and so increases transport distance of the nanoparticles. In this study, the transport of iron oxide nanoparticles (Fe3O4 stabilized with PAA in a one-dimensional porous media (column was investigated. The slurries with concentrations of 20,100 and 500 (mg/L were injected into the bottom of the column under hydraulic gradients of 0.125, 0.375, and 0.625. The results obtained from experiments were compared with the results obtained from numerical solution of advection-dispersion equation based on the classical colloid filtration theory (CFT. The experimental and simulated breakthrough curves showed that CFT is able to predict the transport and fate of iron oxide nanoparticles stabilized with PAA (up to concentration 500 ppm in a porous media.

  16. Selective surface functionalization of polystyrene induced by synchrotron or UV radiation in the presence of oxygen or acrylic acid vapors

    Efficient surface functionalization of Polystyrene (PS) thin films by electromagnetic radiation in combination with a reactive gaseous atmosphere was obtained. Monochromatic synchrotron (SR) or polychromatic UV radiation were used as excitation sources. When SR was used, O2 was introduced after irradiation into the UHV chamber. UV irradiation was carried out keeping a constant flow of O2 or acrylic acid (AA) vapors during the photolysis. FTIR-ATR and XPS-NEXAFS spectra were obtained at the UFRGS and the LNLS, Campinas respectively. PS films were functionalized by monochromatic SR and then expose to O2 at specific transitions such us C 1s →σ*C-C excitation. It was found a high rate of COO, C=O and C-O groups at the surface (> 70%). UV-assisted treatment in the presence of AA vapors showed that an efficient polymerization process took place, such as, it was observed in previous AA low pressure RF plasma treatments. UV-assisted functionalization has the advantage of lower costs and simple set-up compared to plasma treatments. (author)

  17. Dually cross-linked single network poly(acrylic acid) hydrogels with superior mechanical properties and water absorbency.

    Zhong, Ming; Liu, Yi-Tao; Liu, Xiao-Ying; Shi, Fu-Kuan; Zhang, Li-Qin; Zhu, Mei-Fang; Xie, Xu-Ming

    2016-06-28

    Poly(acrylic acid) (PAA) hydrogels with superior mechanical properties, based on a single network structure with dual cross-linking, are prepared by one-pot free radical polymerization. The network structure of the PAA hydrogels is composed of dual cross-linking: a dynamic and reversible ionic cross-linking among the PAA chains enabled by Fe(3+) ions, and a sparse covalent cross-linking enabled by a covalent cross-linker (Bis). Under deformation, the covalently cross-linked PAA chains remain intact to maintain their original configuration, while the Fe(3+)-enabled ionic cross-linking among the PAA chains is broken to dissipate energy and then recombined. It is found that the mechanical properties of the PAA hydrogels are significantly influenced by the contents of covalent cross-linkers, Fe(3+) ions and water, which can be adjusted within a substantial range and thus broaden the applications of the hydrogels. Meanwhile, the PAA hydrogels have excellent recoverability based on the dynamic and reversible ionic cross-linking enabled by Fe(3+) ions. Moreover, the swelling capacity of the PAA hydrogels is as high as 1800 times in deionized water due to the synergistic effects of ionic and covalent cross-linkings. The combination of balanced mechanical properties, efficient recoverability, high swelling capacity and facile preparation provides a new method to obtain high-performance hydrogels. PMID:27230478

  18. TEMPERATURE AND pH RESPONSE, AND SWELLING BEHAVIOR OF POROUS ACRYLONITRILE-ACRYLIC ACID COPOLYMER HYDROGELS

    Jian Huang; Zhi-ming Huang; Yong-zhong Bao; Zhi-xue Weng

    2006-01-01

    Macroporous acrylonitrile-acrylic acid (AN-AA) copolymer hydrogels were synthesized by free-radical solution polymerizations, using ammonium persulfate (APS)/N,N,N',N'-tetramethylethylenediamine (TEMED) redox initiator system and alcohols porogens. The morphology, temperature and pH sensitive swelling behavior, and swelling kinetics of the resulting hydrogels were investigated. It was found that alcohol type and concentration had great influences on the pore structure and porosity of hydrogels. The pore size of hydrogel increases with the moderate increase of the length of alcohol alkyl chain. However, a further increase of alkyl length would result in the formation of cauliflower-like structure and the decrease of pore size. The porosity of hydrogels increases with the increase of porogen concentration in the polymerization medium. The hydrogels with macroporous structure swell or shrink much faster in response to the change of pH in comparison with the conventional hydrogel without macroporous structure. Furthermore, the response rate is closely related to the porosity of the hydrogels, which could be easily controlled by modulating the concentration of the porogen in the medium. The circular swelling behavior of hydrogels indicated the formation of a relaxing three-dimensional network.

  19. Synthesis of silica coated zinc oxide–poly(ethylene-co-acrylic acid) matrix and its UV shielding evaluation

    Ramasamy, Mohankandhasamy [Division of Bionanotechnology, Gachon University, Seongnam 461-701 (Korea, Republic of); Kim, Yu Jun; Gao, Haiyan [Department of Polymer Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Yi, Dong Kee, E-mail: vitalis@mju.ac.kr [Department of Chemistry, Myongji University, Yongin 449-728 (Korea, Republic of); An, Jeong Ho, E-mail: jhahn1us@skku.edu [Department of Polymer Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2014-03-01

    Graphical abstract: - Highlights: • Well layer thickness controlled silica shell was made on ZnO nanoparticles. • PEAA, an interfacial agent is used to make nanocomposite–polymer matrix by twin-screw extruder. • Si-ZnO/PEAA matrix is highly stable and UV protective as compared to ZnO/PEAA matrix. • Nanoparticle embedded polymer matrix is suggested to make UV shielding fabrics with Nylon4. - Abstract: Silica coated zinc oxide nanoparticles (Si-ZnO NPs) (7 nm thick) were synthesized successfully and melt blended with poly(ethylene-co-acrylic acid) (PEAA resin) to improving ultraviolet (UV) shielding of zinc oxide nanoparticles (ZnO NPs). The photostability of both the ZnO NPs and Si-ZnO NPs were analyzed by the difference in photoluminescence (PL) and by methylene blue (MB) degradation. Photo-degradation studies confirmed that Si-ZnO NPs are highly photostable compared to ZnO NPs. The melt blended matrices were characterized by field emission scanning electron microscopy interfaced with energy dispersive X-ray spectroscopy (FE-SEM-EDX). The UV shielding property was analyzed from the transmittance spectra of UV–visible (UV–vis) spectroscopy. The results confirmed fine dispersion of thick Si-ZnO NPs in the entire resin matrix. Moreover, the Si-ZnO/PEAA showed about 97% UV shielding properties than the ZnO/PEAA.

  20. Preparation of mesoporous poly (acrylic acid)/SiO2 composite nanofiber membranes having adsorption capacity for indigo carmine dye

    Xu, Ran; Jia, Min; Li, Fengting; Wang, Hongtao; Zhang, Bingru; Qiao, Junlian

    2012-03-01

    Mesoporous poly (acrylic acid)/SiO2 (PAA/SiO2) composite nanofiber membranes functionalized with mercapto groups were fabricated by a sol-gel electrospinning method, and their adsorption capacity for indigo carmine was investigated. The membranes were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, x-ray powder diffraction (XRD), and nitrogen adsorption-desorption measurement. SEM and TEM observation results showed that the PAA/SiO2 fibers had diameters between 400-800 nm and mesopores with an average pore size of 3.88 nm. The specific surface area of the mesoporous nanofiber membranes was 514.89 m2/g. The characteristic peaks for mercapto group vibration in FTIR and Raman spectra demonstrated that the mercapto groups have been incorporated into the silica skeleton. The adsorption isotherm data of indigo carmine on the membranes fit well with Redlich-Peterson model, and the maximum adsorption capacity calculated was 523.11 mg/g. It was found that the removal rate of indigo carmine by the membranes reached a maximum of 98% in 90 min and the adsorption kinetics followed a pseudo-second-order model. The high adsorption capacity of PAA/SiO2 nanofiber membrane makes it a promising adsorbent for indigo carmine removal from the wastewater.

  1. Preparation and swelling behavior of a novel self-assembled β-cyclodextrin/acrylic acid/sodium alginate hydrogel.

    Huang, Zhanhua; Liu, Shouxin; Zhang, Bin; Wu, Qinglin

    2014-11-26

    A novel biodegradable β-cyclodextrin/acrylic acid/sodium alginate (CSA) hydrogel with a three-dimensional network structure was self-assembled by inverse suspension copolymerization. The CSA resin was pH sensitive and had good water absorption properties in pH 6-8 buffer solutions. At a β-CD:AA:SA mass ratio of 1:9:3 the CSA water absorbency was found to be 1403 g/g and the CSA hydrogel strength was 4.968 N. In 0.005-0.1 mol/L chloride salt and sulfate salt solutions the CSA water absorbencies increased as follows: NaCl>KCl>MgCl2>CaCl2>FeCl3, and Na2SO4>K2SO4>FeSO4>Al2(SO4)3, respectively. The release of water from the CSA hydrogel occurred slowly over 120 h. The biodegradation efficiency of the resin reached 85.3% for Lentinula edodes. The super water absorbency, good salt resistance and excellent water retention properties of CSA make it suitable for application as an agricultural water retention agent in saline soils. PMID:25256504

  2. Fabrication of micro-dot arrays and micro-walls of acrylic acid/melamine resin on aluminum by AFM probe processing and electrophoretic coating

    Kurokawa, S.; Kikuchi, T.; Sakairi, M. [Graduate School of Engineering, Hokkaido University, N-13, W-8, Kita-Ku, Sapporo 060-8628 (Japan); Takahashi, H. [Graduate School of Engineering, Hokkaido University, N-13, W-8, Kita-Ku, Sapporo 060-8628 (Japan)], E-mail: takahasi@elechem1-mc.eng.hokudai.ac.jp

    2008-11-30

    Micro-dot arrays and micro-walls of acrylic acid/melamine resin were fabricated on aluminum by anodizing, atomic force microscope (AFM) probe processing, and electrophoretic deposition. Barrier type anodic oxide films of 15 nm thickness were formed on aluminum and then the specimen was scratched with an AFM probe in a solution containing acrylic acid/melamine resin nano-particles to remove the anodic oxide film locally. After scratching, the specimen was anodically polarized to deposit acrylic acid/melamine resin electrophoretically at the film-removed area. The resin deposited on the specimen was finally cured by heating. It was found that scratching with the AFM probe on open circuit leads to the contamination of the probe with resin, due to positive shifts in the potential during scratching. Scratching of the specimen under potentiostatic conditions at -1.0 V, however, resulted in successful resin deposition at the film-removed area without probe contamination. The rate of resin deposition increased as the specimen potential becomes more positive during electrophoretic deposition. Arrays of resin dots with a few to several tens {mu}m diameter and 100-1000 nm height, and resin walls with 100-1000 nm height and 1 {mu}m width were obtained on specimens by successive anodizing, probe processing, and electrophoretic deposition.

  3. Fabrication of micro-dot arrays and micro-walls of acrylic acid/melamine resin on aluminum by AFM probe processing and electrophoretic coating

    Micro-dot arrays and micro-walls of acrylic acid/melamine resin were fabricated on aluminum by anodizing, atomic force microscope (AFM) probe processing, and electrophoretic deposition. Barrier type anodic oxide films of 15 nm thickness were formed on aluminum and then the specimen was scratched with an AFM probe in a solution containing acrylic acid/melamine resin nano-particles to remove the anodic oxide film locally. After scratching, the specimen was anodically polarized to deposit acrylic acid/melamine resin electrophoretically at the film-removed area. The resin deposited on the specimen was finally cured by heating. It was found that scratching with the AFM probe on open circuit leads to the contamination of the probe with resin, due to positive shifts in the potential during scratching. Scratching of the specimen under potentiostatic conditions at -1.0 V, however, resulted in successful resin deposition at the film-removed area without probe contamination. The rate of resin deposition increased as the specimen potential becomes more positive during electrophoretic deposition. Arrays of resin dots with a few to several tens μm diameter and 100-1000 nm height, and resin walls with 100-1000 nm height and 1 μm width were obtained on specimens by successive anodizing, probe processing, and electrophoretic deposition

  4. Extending framework based on the linear coordination polymers: Alternative chains containing lanthanum ion and acrylic acid ligand

    One-dimensional alternative chains of two lanthanum complexes: [La(L1)3(CH3OH)(H2O)2].5H2O (L1=anion of α-cyano-4-hydroxycinnamic acid ) 1 and [La(L2)3(H2O)2].3H2O (L2=anion of trans-3-(4-methyl-benzoyl)-acrylic acid) 2 were synthesized and structurally characterized by single-crystal X-ray diffraction, element analysis, IR and thermogravimetric analysis. The crystal structure data are as follows for 1: C31H36LaN3O17, triclinic, P-1, a=9.8279(4)A, b=11.8278(5)A, c=17.8730(7)A, α=72.7960(10)o, β=83.3820(10)o, γ=67.1650(10)-bar , Z=2, R1=0.0377, wR2=0.0746; for 2: C33H37LaO14, triclinic, P-1, a=8.7174(5)A, b=9.9377(5)A, c=21.153(2)A, α=81.145(2)o, β=87.591(2)o, γ=67.345(5)o, Z=2, R1=0.0869, wR2=0.220. 1 is a rare example of the alternative chain constructed by syn-syn and anti-syn coordination mode of carboxylato ligand arranged along the chain alternatively. La(III) ions in 2 are linked by two η3-O bridges and four bridges (two η2-O and two η3-O) alternatively. Both of the linear coordination polymers grow into two- and three-dimensional networks by packing through extending hydrogen-bond network directed by ligands

  5. Modification of Poly(Ethylene Terephthalate) Fiber by Grafting of Acrylic Acid/Acrylamide for Removal of Pb+2 from Aqueous Solutions

    A new fibrous adsorbent was prepared by grafting Acrylic Acid /Acryl Amide co-monomers onto Poly(Ethylene Terephthalate) fibers. The resulting sorbent has been characterized by Fourier Transform Infrared spectroscopy, Thermo Gravimetric Analysis, Scanning Electron Microscopy and elemental analysis and studied for the preconcentration and determination of trace Pb+2 ion from water sample. The effects of reaction conditions such as monomer mixture ratio, grafting yield, polymerization. The time and temperature on grafting were investigated. Batch adsorption method was used for the pre concentration studies. Recovery of Pb+2 was 100.2% at optimum conditions. The adsorption capacity of the adsorbent was found 44.1 mg/g for Pb+2.

  6. Adsorption of Methyl Violet and Brilliant Blue onto Poly(vinyl alcohol) Membranes Grafted with N-Vinyl imidazol / Acrylic Acid

    Poly(vinyl alcohol) films were grafted with two monomers using gamma radiation, acrylic acid and N-vinyl imidazole. The ability of these membranes for the adsorption of methyl violet and brilliant blue has been investigated. The data show that untreated or alkali treated membranes adsorb methyl violet; but they did not absorb brilliant blue. In contrast, acidic treated membranes do adsorb brilliant blue, and did not adsorb methyl violet. This indicates that these membranes could be used for the separation of both dyes. Also it was found that the dye uptake increases with increasing the degree of grafting

  7. Radiation Synthesis and Characterization of Polyvinyl alcohol/Acrylic acid Hydrogel and its Amoxicillin drug Delivery application

    Polyvinyl alcohol /Acrylic acid based hydrogels can be synthesized by Gamma radiation technique using 60Co irradiation cell at irradiation dose rate 1.8 Gray/second. The optimum conditions of hydrogel preparation takes place at different factors such as composition ratios of PVA/AAc, different comonomer concentration and different irradiation doses resulting in hydrogel with maximum gel percent as it obtained 98%. The structures of hydrogels were characterized by FTIR analysis. The results can be confirmed the expected structures as well as free radical copolymerization. According to the swelling studies, hydrogels with high content of AAc gave relatively high swelling percent. The hydrogel showed a super adsorbent with swelling capacity 10320 %. Water diffusion into such prepared hydrogel showed a non-Fickian type where a Fickian number was 0.77. This hydrogel was used for the adsorption of amoxicillin drug from their aqueous solutions. The factors affected on the uptake conditions such as ph, time and initial feed concentration on the amoxicillin adsorption capacity of hydrogel was studied depending on Freundlish model of adsorption isotherm.. It was observed that the interaction between drug and ionic comonomers was enhanced in alkaline medium and high initial feed concentration of the drug. The ability of the hydrogel and the affinity of the drug to be adsorbed can be cleared by determining the empirical constants n and k respectively from the logarithmic form of Freundlish equation. The recovery of drug was also investigated in different ph values to study the suitable condition of drug release as drug delivery system.

  8. Nanoclays reinforced glass ionomer cements: dispersion and interaction of polymer grade (PG) montmorillonite with poly(acrylic acid).

    Fareed, Muhammad A; Stamboulis, Artemis

    2014-01-01

    Montmorillonite nanoclays (PGV and PGN) were dispersed in poly(acrylic acid) (PAA) for utilization as reinforcing filler in glass ionomer cements (GICs). Chemical and physical interaction of PAA and nanoclay (PGV and PGN) was studied. PAA–PGV and PAA–PGN solutions were prepared in different weight percent loadings of PGV and PGN nanoclay (0.5-8.0 wt%) via exfoliation-adsorption method. Characterization was carried out by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and fourier transform infrared (FTIR) spectroscopy. XRD results of PAA–PGN demonstrated that the interlayer space expanded from 12.83 to 16.03 Å indicating intercalation whereas the absence of the peak at d(001) in PAA–PGV indicated exfoliation. XPS scans of PGV and PGN nanoclays depicted the main peak of O 1s photoelectron due to Si–O–M (M = Mg, Al, Fe) whereas, Si–O–Al linkages were identified by Si 2p or Si 2s and Al 2p or Al 2s peaks. The disappearance of the Na peak confirmed that PAA molecules exchanged sodium ions present on surface of silicate layers and significantly reduced the electrostatic van-der-Waals forces between silicate plates resulting in intercalation or exfoliation. FTIR spectra of PAA–nanoclay suspensions demonstrated the presence of a new peak at 1,019 cm(-1) associated with Si–O– stretching vibrations which increased with increasing nanoclays concentration. Information concerning the dispersion of nanoclay in PAA aqueous solutions, chemical reaction and increase interlayer space in montmorillonite nanoclay is particularly useful regarding dispersion and reinforcement of nanoclay in PAA. PMID:24077996

  9. Self-assembled poly(ethylene glycol)-co-acrylic acid microgels to inhibit bacterial colonization of synthetic surfaces.

    Wang, Qichen; Uzunoglu, Emel; Wu, Yong; Libera, Matthew

    2012-05-01

    We explored the use of self-assembled microgels to inhibit the bacterial colonization of synthetic surfaces both by modulating surface cell adhesiveness at length scales comparable to bacterial dimensions (∼1 μm) and by locally storing/releasing an antimicrobial. Poly(ethylene glycol) [PEG] and poly(ethylene glycol)-co-acrylic acid [PEG-AA] microgels were synthesized by suspension photopolymerization. Consistent with macroscopic gels, a pH dependence of both zeta potential and hydrodynamic diameter was observed in AA-containing microgels but not in pure PEG microgels. The microgels were electrostatically deposited onto poly(l-lysine) (PLL) primed silicon to form submonolayer surface coatings. The microgel surface density could be controlled via the deposition time and the microgel concentration in the parent suspension. In addition to their intrinsic antifouling properties, after deposition, the microgels could be loaded with a cationic antimicrobial peptide (L5) because of favorable electrostatic interactions. Loading was significantly higher in PEG-AA microgels than in pure PEG microgels. The modification of PLL-primed Si by unloaded PEG-AA microgels reduced the short-term (6 h) S. epidermidis surface colonization by a factor of 2, and the degree of inhibition increased when the average spacing between microgels was reduced. Postdeposition L5 peptide loading into microgels further reduced bacterial colonization to the extent that, after 10 h of S. epidermidis culture in tryptic soy broth, the colonization of L5-loaded PEG-AA microgel-modified Si was comparable to the very small level of colonization observed on macroscopic PEG gel controls. The fact that these microgels can be deposited by a nonline-of-sight self-assembly process and hinder bacterial colonization opens the possibility of modifying the surfaces of topographically complex biomedical devices and reduces the rate of biomaterial-associated infection. PMID:22519439

  10. The Chemical and Physical Properties of Poly(ε-caprolactone) Scaffolds Functionalised with Poly(vinyl phosphonic acid-co-acrylic acid).

    Bassi, A K; Gough, J E; Zakikhani, M; Downes, S

    2011-01-01

    There is a clinical need for a synthetic alternative to bone graft substitute (BGS) derived from demineralised bone matrix. We report the electrospinning of Poly(ε-caprolactone) (PCL) to form a 3-dimensional scaffold for use as a synthetic BGS. Additionally, we have used Poly(vinyl phosphonic acid-co-acrylic acid) (PVPA) to improve bone formation. Fibres were formed using a 10% w/v PCL/acetone solution. Infrared spectroscopy confirmed that the electrospinning process had no effect on the functional groups present in the resulting structure. The electrospun scaffolds were coated with PVPA (PCL/PVPA), and characterised. The stability of the PVPA coating after immersion in culture medium was assessed over 21 days. There was rapid release of the coating until day 2, after which the coating became stable. The wettability of the PCL scaffolds improved significantly, from 123.3 ± 10.8° to 43.3 ± 1.2° after functionalisation with PVPA. The compressive strength of the PCL/PVPA scaffolds (72 MPa) was significantly higher to that of the PCL scaffold (14 MPa), and an intermediate between trabecular and cortical bone (7 MPa and 170 MPa, resp.). The study has demonstrated that the PCL/PVPA scaffold has the desired chemical and biomechanical characteristics required for a material designed to be used as a BGS. PMID:22073379

  11. Preparation of Poly Acrylic Acid-Poly Acrylamide Composite Nanogels by Radiation Technique

    Parisa Ghorbaniazar

    2015-06-01

    Full Text Available Purpose: Nanogel, a nanoparticle prepared from a cross-linked hydrophilic polymer network, has many biomedical applications. A radiation technique has recently been introduced as one of the appropriate methods for the preparation of polymeric nanogels due to its additive-free initiation and easy control procedure. Methods: We have investigated the formation of nano-sized polymeric gels, based on the radiation-induced inter- and intra-molecular cross-linking of the inter-polymer complex (IPC of polyacrylamide (PAAm and polyacrylic acide (PAAc. Results: The results indicated that the prepared polymeric complex composed of PAAm and PAAc was converted into nanogel by irradiation under different doses (1, 3, 5 and 7 kGy. This was due to inter- and intra-molecular cross-linking at the range of 446-930 nm as characterized by the photon correlation spectroscopy method. Increasing the irradiation dose reduced the size of nanoparticles to 3 kGy; however, the higher doses increased the size and size distribution. Scanning electron microscopy images indicated the nanogel formation in the reported size by particle size and showed the microcapsule structure of the prepared nanogels. Biocompatibility of nanogels were assessed and proved by MTT assay. Conclusion: It was concluded that low dose irradiation can be successfully applied for nanometre-ranged hydrogel.

  12. Nacre-inspired integrated strong and tough reduced graphene oxide-poly(acrylic acid) nanocomposites

    Wan, Sijie; Hu, Han; Peng, Jingsong; Li, Yuchen; Fan, Yuzun; Jiang, Lei; Cheng, Qunfeng

    2016-03-01

    Inspired by the relationship between interface interactions and the high performance mechanical properties of nacre, a strong and tough nacre-inspired nanocomposite was demonstrated based on graphene oxide (GO) and polyacrylic acid (PAA) prepared via a vacuum-assisted filtration self-assembly process. The abundant hydrogen bonding between GO and PAA results in both high strength and toughness of the bioinspired nanocomposites, which are 2 and 3.3 times higher than that of pure reduced GO film, respectively. In addition, the effect of environmental relative humidity on the mechanical properties of bioinspired nanocomposites is also investigated, and is consistent with previous theoretical predictions. Moreover, this nacre-inspired nanocomposite also displays high electrical conductivity of 108.9 S cm-1. These excellent physical properties allow this type of nacre-inspired nanocomposite to be used in many applications, such as flexible electrodes, aerospace applications, and artificial muscles etc. This nacre-inspired strategy also opens an avenue for constructing integrated high performance graphene-based nanocomposites in the near future.

  13. Grafting Copolymerization of Styrene and Acrylic Acid onto Pre-irradiated Polypropylene Fabric%预辐射聚丙烯纤维接枝苯乙烯和丙烯酸的研究

    陈捷; 杨黎明; 吴明红; 卢永畅

    2000-01-01

    Grafting copolymerization of styrene and acrylic acid onto polypropylene fabric had been studied by using a pre-irradiation technique. The polypropylene fabric samples were irradiated by γ -ray and electron beam under the conditions of air and nitrogen gas, respectively. The effect of absorbed dose, monomer concentration in solvent, reaction temperature and reaction time on the degree of grafting were determined. The effects of metallic salts and sulphuric acid on the grafting yield of acrylic acid were also examined. The samples irradiated by electron beam give a much higher degree of grafting than those by γ -ray when styrene was grafted to polypropylene fabric. However, the grafting yield of acrylic acid on polypropylene fabric in the presence of metallic salts and sulfuric acid showed the opposite results from the case of styrene. This effect is reasonably interpreted by assuming that the grafting is dominated by trapped radicals and peroxides in pre-irradiated polypropylene.

  14. Grafting Copolymerization of Styrene and Acrylic Acid onto Pre-irradiated Polypropylene Fabric%预辐射聚丙烯纤维接枝苯乙烯和丙烯酸的研究

    陈捷; 杨黎明; 吴明红; 卢永畅

    2001-01-01

    Grafting copolymerization of styrene and acrylic acid onto polypropylene fabric had been studied by using a pre-irradiation technique. The polypropylene fabric samples were irradiated by γ -ray and electron beam under the conditions of air and nitrogen gas, respectively. The effect of absorbed dose, monomer concentration in solvent, reaction temperature and reaction time on the degree of grafting were determined. The effects of metallic salts and sulphuric acid on the grafting yield of acrylic acid were also examined. The samples irradiated by electron beam give a much higher degree of grafting than those by γ -ray when styrene was grafted to polypropylene fabric. However, the grafting yield of acrylic acid on polypropylene fabric in the presence of metallic salts and sulfuric acid showed the opposite results from the case of styrene. This effect is reasonably interpreted by assuming that the grafting is dominated by trapped radicals and peroxides in pre-irradiated polypropylene.

  15. Superabsorbent hydrogels via graft polymerization of acrylic acid from chitosan-cellulose hybrid and their potential in controlled release of soil nutrients.

    Essawy, Hisham A; Ghazy, Mohamed B M; El-Hai, Farag Abd; Mohamed, Magdy F

    2016-08-01

    Superabsorbent polymers fabricated via grafting polymerization of acrylic acid from chitosan (CTS) yields materials that suffer from poor mechanical strength. Hybridization of chitosan with cellulose (Cell) via chemical bonding using thiourea formaldehyde resin increases the flexibility of the produced hybrid (CTS/Cell). The hybridization process and post graft polymerization of acrylic acid was followed using Fourier transform infrared (FTIR). Also, the obtained structures were homogeneous and exhibited uniform surface as could be shown from imaging with scanning electron microscopy (SEM). Thus, the polymers derived from the grafting of polyacrylic acid from (CTS/Cell) gave rise to much more mechanically robust structures ((CTS/Cell)-g-PAA) that bear wide range of pH response due to presence of chitosan and polyacrylic acid in one homogeneous entity. Additionally, the obtained structures possessed greater water absorbency 390, 39.5g/g in distilled water and saline (0.9wt.% NaCl solution), respectively, and enhanced retention potential even at elevated temperatures as revealed by thermogravimetric analysis (TGA). This could be explained by the high grafting efficiency (GE%), 86.4%, and grafting yield (GY%), 750%. The new superabsorbent polymers proved to be very efficient devices for controlled release of fertilizers into the soil which expands their use in agriculture and horticultural applications. PMID:27126169

  16. Thermo- and pH-sensitive gel membranes based on poly-(acryloyl-L-proline methyl ester)-graft-poly(acrylic acid) for selective permeation of metal ions

    Thermo- and pH-responsive gel membranes were synthesized by γ-ray grafting of pH-responsive poly(acrylic acid) (AAc) onto thermo-responsive polymer gel of acryloyl-L-proline methyl ester (A-ProOMe). The gel membranes of poly(A-ProOMe) with 15 mol% graft chains of AAc exhibited both thermo- and pH-responses. Under the condition (pH 6.0, 30 deg. C) in which the thermo-sensitive unit shrinks and the pH-sensitive unit swells, the selective permeation of Li ion over Co and Ni ions can be achieved

  17. Thermo- and pH-sensitive gel membranes based on poly-(acryloyl-L-proline methyl ester)-graft-poly(acrylic acid) for selective permeation of metal ions

    Hasegawa, Shin; Ohashi, Hitoshi; Maekawa, Yasunari; Katakai, Ryoichi; Yoshida, Masaru E-mail: katsu@taka.jaeri.go.jp

    2005-04-01

    Thermo- and pH-responsive gel membranes were synthesized by {gamma}-ray grafting of pH-responsive poly(acrylic acid) (AAc) onto thermo-responsive polymer gel of acryloyl-L-proline methyl ester (A-ProOMe). The gel membranes of poly(A-ProOMe) with 15 mol% graft chains of AAc exhibited both thermo- and pH-responses. Under the condition (pH 6.0, 30 deg. C) in which the thermo-sensitive unit shrinks and the pH-sensitive unit swells, the selective permeation of Li ion over Co and Ni ions can be achieved.

  18. Preparation of pH- and thermo-sensitive hydrogel by two-step grafting of acrylamide and acrylic acid onto preirradiated polyethylene film

    Two-step grafting reaction of acrylamide (AAm) and acrylic acid (AAc) onto preirradiated polyethylene (PE) film were performed. The effects of irradiation dose, reaction temperature and reaction time on the grafting yield were studied. The effect of reaction time of the first step grafting on the yield of the second step grafting was also evaluated. The original and the irradiated PE films were tested by Fourier transform infrared (FTIR) spectroscopy in the attenuated total reflectance mode (ATR). The AAm and AAc grafted PE film appeared thermo- and pH-sensitive which are similar to the interpenetrating polymer network hydrogel. (author)

  19. Development of a platform for nasal delivery of peptides and vaccines using powder carriers based on starch/poly(acrylic) acid

    Coucke, Delphine

    2009-01-01

    The interest in and importance of systemic drug delivery via the nasal route have expanded in recent decades since nasal administration offers an interesting alternative for the conventional oral and parenteral drug delivery routes. In this thesis, the nasal route was selected as an alternative route for peptide and vaccine delivery. A spray-dried combination of maize starch (Amioca®) and a cross-linked acrylic acid-based polymer (Carbopol® 974P) was used as powder carrier to amplify the ...

  20. TiO2 supported over porous silica photocatalysts for pesticide degradation using solar light: Part 2. Silica prepared using acrylic acid emulsion

    An acrylic acid emulsion mixture is used for synthesis of novel porous silica (E-Si) material. The photocatalytic activity of TiO2 under solar light irradiation for isoproturon (herbicide) degradation is drastically increased when dispersed over E-Si support using solid state dispersion (SSD) technique. The composite material is characterized by XRD, nitrogen adsorption-desorption isotherms, UV-vis DRS, SEM and TEM measurements. The photocatalytic activities of the composite catalysts are evaluated for different parameters. The 5 wt% TiO2/E-Si is found to be highly active for isoproturon degradation.

  1. Usefulness of microporous hydrophobic polypropylene membranes after plasma-induced graft polymerization of acrylic acid for high-power nickel-cadmium batteries

    Commercial microporous polypropylene (PP) membranes were modified by plasma-induced graft polymerization of acrylic acid (AAc) under UV irradiation. Under optimized conditions obtained membranes are hydrophilic and may be serviceable as separator in nickel-cadmium cell. Electrolytic resistance of modified membranes is evaluated and compared with that of commercial separators: conventional cellophane separation and hydrophilic polypropylene separation (Celgard 3501). This paper reports the maximum power test data for nickel-cadmium cells equipped with different separators. Cells with modified PP membrane show very good high-rate performance

  2. Synthesis of polyaniline catalysed by Cu(I), Ni(II) and Fe(II) supported on the polyethylene-i-acrylic acid copolymer

    In this study the active sites of acrylic acid (AA) were grafted in low density polyethylene (PEBD) using gamma radiation. Subsequently, the graft copolymer PEBD-i-AA was coordinated with different metals such as copper, nickel and iron. The organometallic copolymers so formed were used as catalysts in the aniline polymerization reaction. Finally, it was realized the characterization of the obtained products, determining their thermal properties, copolymer graft percentage, quantification of the metal contained in the complex as well as polymerization and electric conductivity percentages of the poly aniline film. (Author)

  3. Effect of chemical composition on corneal tissue response to photopolymerized materials comprising 2-hydroxyethyl methacrylate and acrylic acid

    The purpose of this work was to investigate the relationship between the feed composition of 2-hydroxyethyl methacrylate (HEMA)/acrylic acid (AAc) and hydrogel material compatibility towards ocular anterior segment tissues, particularly the corneal endothelium. The monomer solutions of HEMA and AAc were mixed at varying volume ratios of 92:0, 87:5, 82:10, 77:15, and 72:20, and were subjected to UV irradiation. Then, the 7-mm-diameter membrane implants made from photopolymerized materials were placed into the ocular anterior chamber for 4 days and assessed by biomicroscopic examinations, corneal thickness measurements, and quantitative real-time reverse transcription polymerase chain reaction analyses. The poly(HEMA-co-AAc) implants prepared from the solution mixture containing 0–10 vol.% AAc displayed good biocompatibility. However, with increasing volume ratio of AAc and HEMA from 15:77 to 20:72, the enhanced inflammatory response, decreased endothelial cell density, and increased ocular score and corneal thickness were observed, probably due to the influence of surface charge of copolymer membranes. On the other hand, the ionic pump function of corneal endothelium exposed to photopolymerized membranes was examined by analyzing the Na+,K+-ATPase alpha 1 subunit (ATP1A1) expression level. The presence of the implants having higher amount of AAc incorporated in the copolymers (i.e., 15.1 to 24.7 μmol) and zeta potential (i.e., -38.6 to − 56.5 mV) may lead to abnormal transmembrane transport. It is concluded that the chemical composition of HEMA/AAc has an important influence on the corneal tissue responses to polymeric biomaterials. - Highlights: • We examine the corneal tissue responses to photopolymerized biomaterials. • Carboxyl groups in copolymers increased with increasing volume ratio of AAc/HEMA. • 15–20 vol.% AAc raised ocular score and caused corneal endothelial loss and edema. • High anionic charge density stimulated inflammation and

  4. Effect of chemical composition on corneal cellular response to photopolymerized materials comprising 2-hydroxyethyl methacrylate and acrylic acid

    Characterization of corneal cellular response to hydrogel materials is an important issue in ophthalmic applications. In this study, we aimed to investigate the relationship between the feed composition of 2-hydroxyethyl methacrylate (HEMA)/acrylic acid (AAc) and material compatibility towards corneal stromal and endothelial cells. The monomer solutions of HEMA and AAc were mixed at varying volume ratios of 92:0, 87:5, 82:10, 77:15, and 72:20, and were subjected to UV irradiation. Results of electrokinetic measurements showed that an increase in absolute zeta potential of photopolymerized membranes is observed with increasing the volume ratios of AAc/HEMA. Following 4 days of incubation with various hydrogels, the primary rabbit corneal stromal and endothelial cell cultures were examined for viability, proliferation, and pro-inflammatory gene expression. The samples prepared from the solution mixture containing 0–10 vol.% AAc displayed good cytocompatibility. However, with increasing volume ratio of AAc and HEMA from 15:77 to 20:72, the decreased viability, inhibited proliferation, and stimulated inflammation were noted in both cell types, probably due to the stronger charge–charge interactions. On the other hand, the ionic pump function of corneal endothelial cells exposed to photopolymerized membranes was examined by analyzing the Na+,K+-ATPase alpha 1 subunit (ATP1A1) expression level. The presence of material samples having higher anionic charge density (i.e., zeta potential of − 38 to − 56 mV) may lead to abnormal transmembrane transport. It is concluded that the chemical composition of HEMA/AAc has an important influence on the corneal stromal and endothelial cell responses to polymeric biomaterials. - Highlights: • We examine the corneal cellular responses to photopolymerized biomaterials. • Charge density of membranes was increased with increasing volume ratio of AAc/HEMA. • 15–20 vol.% AAc decreased viability and proliferation of all

  5. Effect of chemical composition on corneal tissue response to photopolymerized materials comprising 2-hydroxyethyl methacrylate and acrylic acid

    Lai, Jui-Yang, E-mail: jylai@mail.cgu.edu.tw

    2014-01-01

    The purpose of this work was to investigate the relationship between the feed composition of 2-hydroxyethyl methacrylate (HEMA)/acrylic acid (AAc) and hydrogel material compatibility towards ocular anterior segment tissues, particularly the corneal endothelium. The monomer solutions of HEMA and AAc were mixed at varying volume ratios of 92:0, 87:5, 82:10, 77:15, and 72:20, and were subjected to UV irradiation. Then, the 7-mm-diameter membrane implants made from photopolymerized materials were placed into the ocular anterior chamber for 4 days and assessed by biomicroscopic examinations, corneal thickness measurements, and quantitative real-time reverse transcription polymerase chain reaction analyses. The poly(HEMA-co-AAc) implants prepared from the solution mixture containing 0–10 vol.% AAc displayed good biocompatibility. However, with increasing volume ratio of AAc and HEMA from 15:77 to 20:72, the enhanced inflammatory response, decreased endothelial cell density, and increased ocular score and corneal thickness were observed, probably due to the influence of surface charge of copolymer membranes. On the other hand, the ionic pump function of corneal endothelium exposed to photopolymerized membranes was examined by analyzing the Na{sup +},K{sup +}-ATPase alpha 1 subunit (ATP1A1) expression level. The presence of the implants having higher amount of AAc incorporated in the copolymers (i.e., 15.1 to 24.7 μmol) and zeta potential (i.e., -38.6 to − 56.5 mV) may lead to abnormal transmembrane transport. It is concluded that the chemical composition of HEMA/AAc has an important influence on the corneal tissue responses to polymeric biomaterials. - Highlights: • We examine the corneal tissue responses to photopolymerized biomaterials. • Carboxyl groups in copolymers increased with increasing volume ratio of AAc/HEMA. • 15–20 vol.% AAc raised ocular score and caused corneal endothelial loss and edema. • High anionic charge density stimulated inflammation

  6. Surface modification of aramid fiber by plasma induced vapor phase graft polymerization of acrylic acid. I. Influence of plasma conditions

    Wang, C.X., E-mail: cxwang@mail.dhu.edu.cn [College of Textiles and Clothing, Yancheng Institute of Technology, Jiangsu 224003 (China); School of Textile and Clothing, Nantong University, Jiangsu 226019 (China); Du, M. [College of Textiles and Clothing, Yancheng Institute of Industry Technology, Jiangsu 224000 (China); Lv, J.C.; Zhou, Q.Q. [College of Textiles and Clothing, Yancheng Institute of Technology, Jiangsu 224003 (China); Ren, Y. [School of Textile and Clothing, Nantong University, Jiangsu 226019 (China); Liu, G.L.; Gao, D.W. [College of Textiles and Clothing, Yancheng Institute of Technology, Jiangsu 224003 (China); Jin, L.M. [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201204 (China)

    2015-09-15

    Highlights: • Aramid fiber surface was modified by PIVPGP of AA to improve wettability, adhesion. • Surface modification effect by PIVPGP of AA increased and then decreased with time. • Surface modification effect increased and then stayed unaltered with output power. • Ar plasma was the most effective in PIVPGP of AA on aramid fiber surface. • In studied range, optimum technology of PIVPGP of AA: Ar plasma, 15 min, 300 W. - Abstract: Plasma induced vapor phase graft polymerization (PIVPGP) method was applied to modify aramid fiber surface. In this study, aramid fibers were pretreated under various plasma conditions such as different treatment times, output powers and working gases to see how these plasma processing parameters influenced the PIVPGP of acrylic acid (AA) on aramid fiber surface and its surface structure and properties. The analysis results of atomic force microscope (AFM) and X-ray photoelectron spectroscope (XPS) showed the increase of surface roughness and the introduction of O=C−OH, which confirmed that the PIVPGP of AA on aramid fiber surface was achieved. The contact angle and interfacial shear strength (IFSS) of the aramid fibers modified by PIVPGP of AA prominently decreased and increased, respectively, indicating the obvious improvements of surface wettability and adhesion between aramid fiber and matrix. The surface modification effects of aramid fiber by PIVPGP of AA firstly increased and then after 15 min slightly decreased with the increasing plasma treatment time, and but firstly increased and then after 300 W nearly remained unchanged with the increasing output power, respectively. Among different working gases, Ar plasma occupied first place, O{sub 2} plasma and N{sub 2} plasma came second and third in the aspect of PIVPGP of AA on aramid fiber surface, respectively. It could be concluded that the PIVPGP of AA on aramid fiber surface could effectively improve surface wettability and adhesion. Plasma conditions had signally

  7. Surface modification of aramid fiber by plasma induced vapor phase graft polymerization of acrylic acid. I. Influence of plasma conditions

    Highlights: • Aramid fiber surface was modified by PIVPGP of AA to improve wettability, adhesion. • Surface modification effect by PIVPGP of AA increased and then decreased with time. • Surface modification effect increased and then stayed unaltered with output power. • Ar plasma was the most effective in PIVPGP of AA on aramid fiber surface. • In studied range, optimum technology of PIVPGP of AA: Ar plasma, 15 min, 300 W. - Abstract: Plasma induced vapor phase graft polymerization (PIVPGP) method was applied to modify aramid fiber surface. In this study, aramid fibers were pretreated under various plasma conditions such as different treatment times, output powers and working gases to see how these plasma processing parameters influenced the PIVPGP of acrylic acid (AA) on aramid fiber surface and its surface structure and properties. The analysis results of atomic force microscope (AFM) and X-ray photoelectron spectroscope (XPS) showed the increase of surface roughness and the introduction of O=C−OH, which confirmed that the PIVPGP of AA on aramid fiber surface was achieved. The contact angle and interfacial shear strength (IFSS) of the aramid fibers modified by PIVPGP of AA prominently decreased and increased, respectively, indicating the obvious improvements of surface wettability and adhesion between aramid fiber and matrix. The surface modification effects of aramid fiber by PIVPGP of AA firstly increased and then after 15 min slightly decreased with the increasing plasma treatment time, and but firstly increased and then after 300 W nearly remained unchanged with the increasing output power, respectively. Among different working gases, Ar plasma occupied first place, O2 plasma and N2 plasma came second and third in the aspect of PIVPGP of AA on aramid fiber surface, respectively. It could be concluded that the PIVPGP of AA on aramid fiber surface could effectively improve surface wettability and adhesion. Plasma conditions had signally influence on

  8. Directed self-assembly of poly(styrene)-block-poly(acrylic acid) copolymers for sub-20nm pitch patterning

    Cheng, Jing; Lawson, Richard A.; Yeh, Wei-Ming; Jarnagin, Nathan D.; Peters, Andrew; Tolbert, Laren M.; Henderson, Clifford L.

    2012-03-01

    Directed self-assembly (DSA) of block copolymers is a promising technology for extending the patterning capability of current lithographic exposure tools. For example, production of sub-40 nm pitch features using 193nm exposure technologies is conceivably possible using DSA methods without relying on time consuming, challenging, and expensive multiple patterning schemes. Significant recent work has focused on demonstration of the ability to produce large areas of regular grating structures with low numbers of defects using self-assembly of poly(styrene)-b-poly(methyl methacrylate) copolymers (PS-b-PMMA). While these recent results are promising and have shown the ability to print pitches approaching 20 nm using DSA, the ability to advance to even smaller pitches will be dependent upon the ability to develop new block copolymers with higher χ values and the associated alignment and block removal processes required to achieve successful DSA with these new materials. This paper reports on work focused on identifying higher χ block copolymers and their associated DSA processes for sub-20 nm pitch patterning. In this work, DSA using polystyrene-b-polyacid materials has been explored. Specifically, it is shown that poly(styrene)-b-poly(acrylic acid) copolymers (PS-b-PAA) is one promising material for achieving substantially smaller pitch patterns than those possible with PS-b-PMMA while still utilizing simple hydrocarbon polymers. In fact, it is anticipated that much of the learning that has been done with the PS-b-PMMA system, such as development of highly selective plasma etch block removal procedures, can be directly leveraged or transferred to the PS-b-PAA system. Acetone vapor annealing of PS-b-PAA (Mw=16,000 g/mol with 50:50 mole ratio of PS:PAA) and its self-assembly into a lamellar morphology is demonstrated to generate a pattern pitch size (L0) of 21 nm. The χ value for PS-b-PAA was estimated from fingerprint pattern pitch data to be approximately 0.18 which

  9. Effect of chemical composition on corneal cellular response to photopolymerized materials comprising 2-hydroxyethyl methacrylate and acrylic acid

    Lai, Jui-Yang, E-mail: jylai@mail.cgu.edu.tw

    2013-10-15

    Characterization of corneal cellular response to hydrogel materials is an important issue in ophthalmic applications. In this study, we aimed to investigate the relationship between the feed composition of 2-hydroxyethyl methacrylate (HEMA)/acrylic acid (AAc) and material compatibility towards corneal stromal and endothelial cells. The monomer solutions of HEMA and AAc were mixed at varying volume ratios of 92:0, 87:5, 82:10, 77:15, and 72:20, and were subjected to UV irradiation. Results of electrokinetic measurements showed that an increase in absolute zeta potential of photopolymerized membranes is observed with increasing the volume ratios of AAc/HEMA. Following 4 days of incubation with various hydrogels, the primary rabbit corneal stromal and endothelial cell cultures were examined for viability, proliferation, and pro-inflammatory gene expression. The samples prepared from the solution mixture containing 0–10 vol.% AAc displayed good cytocompatibility. However, with increasing volume ratio of AAc and HEMA from 15:77 to 20:72, the decreased viability, inhibited proliferation, and stimulated inflammation were noted in both cell types, probably due to the stronger charge–charge interactions. On the other hand, the ionic pump function of corneal endothelial cells exposed to photopolymerized membranes was examined by analyzing the Na{sup +},K{sup +}-ATPase alpha 1 subunit (ATP1A1) expression level. The presence of material samples having higher anionic charge density (i.e., zeta potential of − 38 to − 56 mV) may lead to abnormal transmembrane transport. It is concluded that the chemical composition of HEMA/AAc has an important influence on the corneal stromal and endothelial cell responses to polymeric biomaterials. - Highlights: • We examine the corneal cellular responses to photopolymerized biomaterials. • Charge density of membranes was increased with increasing volume ratio of AAc/HEMA. • 15–20 vol.% AAc decreased viability and proliferation

  10. Acrylates and methacrylates of formal-glycerine

    Present article is devoted acrylates and methacrylates of formal-glycerine. The formal-glycerine was obtained in the form of mixture of isomers 1.2 and 1.3 from glycerine and paraform with hydrochloric acid. The structure of obtained acrylates and methacrylates is studied by means of molecular refraction, element analysis and infrared spectroscopy.

  11. Synthesis and characterization of antigenic influenza A M2e protein peptide-poly(acrylic) acid bioconjugate and determination of toxicity in vitro.

    Kilinc, Yasemin Budama; Akdeste, Zeynep Mustafaeva; Koc, Rabia Cakir; Bagirova, Melahat; Allahverdiyev, Adil

    2014-01-01

    The influenza A virus is a critical public health problem that causes epidemics and pandemics, and occurs widely all over the world. Various vaccines against the virus have not provided a solution to the problem. Different approaches, particularly M2e peptide-based vaccines, are available for developing universal vaccines against influenza A. However, it is important to select a suitable carrier to obtain an effective vaccine. Accordingly, studies on the usage of various carriers are ongoing. Particularly, polymer-based carriers have gained importance due to both drug delivery and adjuvant effects. Therefore, bioconjugate of the M2e protein peptide from the influenza A virus covalent bonded with poly(acrylic) acid was synthesized in our study for the first time. The characterization was performed using size-exclusion chromatography and fluorescence spectroscopy; subsequently, it was found that the bioconjugate of the examined lower doses (0.05 and 0.5 mg/ml) have no toxic effects on human cell lines. These results suggest that, in the future, the poly(acrylic) acid bioconjugate of the M2e peptide should be studied in vivo for universal vaccine development against the influenza A virus. PMID:25482080

  12. Effect of Mole Percentage of Crosslinker of Silver-poly(N-isopropylacrylamide-co-acrylic acid Hybrid Microgels on Catalytic Reduction of Nitrobenzene

    Zahoor H. FAROOQI

    2015-02-01

    Full Text Available Poly(N-isopropylacrylamide-co-acrylic acid microgels [P(NIPAM-co-AAc] with 2, 4, 6 and 8 mole percentage of N,N-methylene-bis-acrylamide were used as micro-reactors for the fabrication of Ag nanoparticles using the in situ reduction method. The pure and hybrid microgels were characterized by Fourier transform infrared and Ultraviolet-Visible spectroscopies. Silver-poly(N-isopropylacrylamide-co-acrylic acid hybrid microgels [Ag-P(NIPAM-co-AAc] with different crosslinker contents were used as catalysts for reduction of nitrobenzene (NB in aqueous medium in order to investigate the effect of crosslinker content on the value of apparent rate constant (kapp. 0.041, 0.146, 0.2388 and 0.255 min-1 were found as values of kapp for catalytic reduction of NB using hybrid microgels with 2, 4, 6 and 8 mole percentage of crosslinker, respectively. The effect of crosslinker feed content of hybrid microgels on catalytic activity for reduction of NB was compared to that of reduction of p-nitrophenol in aqueous medium.

  13. Thermal and FTIR analysis of the miscibility and phase behaviour of poly (isobutyl methacrylate-co-4-vinylpyridine)/poly (styrene-co-acrylic acid) systems

    Hadj-Hamou, Assia Siham; Habi, Abderrahmane [Laboratoire des Materiaux Polymeres, Faculte de Chimie, Universite des Sciences et de la Technologie Houari Boumediene, B.P. 32, El Alia, Algiers 16111 (Algeria); Djadoun, Said, E-mail: matpolylab@yahoo.fr [Laboratoire des Materiaux Polymeres, Faculte de Chimie, Universite des Sciences et de la Technologie Houari Boumediene, B.P. 32, El Alia, Algiers 16111 (Algeria)

    2010-01-10

    The miscibility and phase behaviour of poly (isobutyl methacrylate-co-4-vinylpyridine) containing 20 mol% of 4-vinylpyridine (IBM4VP20) and poly (styrene-co-acrylic acid) containing 27 or 32 mol% of acrylic acid (SAA27 or SAA32) mixtures were investigated by DSC, TGA and FTIR spectroscopy in the 25-180 {sup o}C temperature range. The results showed that sufficient specific carboxyl-pyridine hydrogen bonding interactions occurred between these copolymers and led to miscible blends as cast from THF and to inter-polymer complexes of significantly improved thermal stability when butan-2-one is the common solvent. The self-association effect on the inter-polymer interactions was evidenced by the decrease of complexation yields, observed when the carboxylic content is increased above 27 mol% as with SAA32. The trend of phase behaviour predicted by a thermodynamic analysis of the specific interactions of hydrogen bonding type that occurred between the two components of the SAA27/IBM4VP20 blends, neglecting the weak carboxyl-ester interactions and the functional group accessibility effect, carried out using the Painter-Coleman association model that considers the screening effects, is in a fair agreement with the experimental results. Moreover an LCST is predicted to occur at relatively high temperature.

  14. Thermal and FTIR analysis of the miscibility and phase behaviour of poly (isobutyl methacrylate-co-4-vinylpyridine)/poly (styrene-co-acrylic acid) systems

    The miscibility and phase behaviour of poly (isobutyl methacrylate-co-4-vinylpyridine) containing 20 mol% of 4-vinylpyridine (IBM4VP20) and poly (styrene-co-acrylic acid) containing 27 or 32 mol% of acrylic acid (SAA27 or SAA32) mixtures were investigated by DSC, TGA and FTIR spectroscopy in the 25-180 oC temperature range. The results showed that sufficient specific carboxyl-pyridine hydrogen bonding interactions occurred between these copolymers and led to miscible blends as cast from THF and to inter-polymer complexes of significantly improved thermal stability when butan-2-one is the common solvent. The self-association effect on the inter-polymer interactions was evidenced by the decrease of complexation yields, observed when the carboxylic content is increased above 27 mol% as with SAA32. The trend of phase behaviour predicted by a thermodynamic analysis of the specific interactions of hydrogen bonding type that occurred between the two components of the SAA27/IBM4VP20 blends, neglecting the weak carboxyl-ester interactions and the functional group accessibility effect, carried out using the Painter-Coleman association model that considers the screening effects, is in a fair agreement with the experimental results. Moreover an LCST is predicted to occur at relatively high temperature.

  15. Spray-dried powders of starch and crosslinked poly(acrylic acid) as carriers for nasal delivery of inactivated influenza vaccine.

    Coucke, D; Schotsaert, M; Libert, C; Pringels, E; Vervaet, C; Foreman, P; Saelens, X; Remon, J P

    2009-02-18

    Mucosal vaccination has several advantages over parenteral vaccination. In this study, viscosity-enhancing mucosal delivery systems for the induction of an adaptive immune response against viral antigen were investigated. Powder formulations based on spray-dried mixtures of starch (Amioca)/poly(acrylic acid) (Carbopol 974P) in different ratios were used as carriers of the viral antigen. A comparison of these formulations for intranasal delivery of heat-inactivated influenza virus combined with LTR192G adjuvant was made in vivo in a rabbit model. Individual rabbit sera were tested for seroconversion against hemagglutinin (HA), the major surface antigen of influenza. The powder vaccine formulations were able to induce systemic anti-HA IgG responses. The presence of Carbopol 974P improved the kinetics of the immune responses and the level of IgG titers in a dose-dependent way which was correlated with moderately irritating capacities of the formulation. In contrast, mucosal IgA responses were not detected. In conclusion, it was demonstrated that the use of bioadhesive carriers based on Amioca starch and poly(acrylic acid) facilitates the induction of a systemic anti-HA antibody response after intranasal vaccination with a whole virus influenza vaccine. PMID:19114075

  16. Synthesis and magnetic heating characteristics of thermoresponsive poly (N-isopropylacrylamide-co-acrylic acid)/nano Fe3O4 nanparticles

    In this work the synthesis of thermo-sensitive polymer coated magnetic nanoparticles and their inductive heating have been studied. Poly (N-isopropylacrylamide-co-acrylic acid) (NA) polymers were first synthesized by emulsion polymerization of poly(N-isopropylacrylamide) (NIP) in water and followed by encapsulating magnetic nanoparticles (MNPs). As increasing the concentration of acrylic acid (AA), the lower critical solution temperature (LCST) increased, so that with 150% of AA (molar ratio) the LCST reached 42 °C, which is close to the temperature of hyperthermia treatment. Magnetization and ac susceptibility measurements were conducted to depict some characteristics of the NIP-MNPs and NA-MNPs that are related with the loss power. Attempts to analyze the rate of magnetic inductive heating were performed to show the Brownian relaxation origin of additional heat source created by the magnetite nanoparticles capped with thermosensitive polymers. Our results suggest that these thermo-sensitive polymer-coated magnetic nanoparticles show a potential for hyperthermia and drug delivery application. (paper)

  17. Synthesis and magnetic heating characteristics of thermoresponsive poly (N-isopropylacrylamide-co-acrylic acid)/nano Fe3O4 nanparticles

    Thu Trang Mai, Thi; Le, Thi Hong Phong; Pham, Hong Nam; Do, Hung Manh; Phuc Nguyen, Xuan

    2014-12-01

    In this work the synthesis of thermo-sensitive polymer coated magnetic nanoparticles and their inductive heating have been studied. Poly (N-isopropylacrylamide-co-acrylic acid) (NA) polymers were first synthesized by emulsion polymerization of poly(N-isopropylacrylamide) (NIP) in water and followed by encapsulating magnetic nanoparticles (MNPs). As increasing the concentration of acrylic acid (AA), the lower critical solution temperature (LCST) increased, so that with 150% of AA (molar ratio) the LCST reached 42 °C, which is close to the temperature of hyperthermia treatment. Magnetization and ac susceptibility measurements were conducted to depict some characteristics of the NIP-MNPs and NA-MNPs that are related with the loss power. Attempts to analyze the rate of magnetic inductive heating were performed to show the Brownian relaxation origin of additional heat source created by the magnetite nanoparticles capped with thermosensitive polymers. Our results suggest that these thermo-sensitive polymer-coated magnetic nanoparticles show a potential for hyperthermia and drug delivery application.

  18. New oil modified acrylic polymer for pH sensitive drug release: Experimental results and statistical analysis

    Panja, N.; Chattopadhyay, A.K.

    2014-01-01

    We report results of an experimental study, complemented by detailed statistical analysis of the experimental data, on the development of a more effective control method of drug delivery using a pH sensitive acrylic polymer. New copolymers based on acrylic acid and fatty acid are constructed from dodecyl castor oil and a tercopolymer based on methyl methacrylate, acrylic acid and acryl amide were prepared using this new approach. Water swelling characteristics of fatty acid, acrylic acid copo...

  19. STUDY ON POLYMER-RARE EARTH METAL ION COMPLEXES I. FLUORESCENT PROPERTIES OF POLY(ACRYLIC ACID-CO-4-VINYLPYRIDINE)-RARE EARTH METAL COMPLEXES

    LU Hong; FANG Shibi; JIANG Yingyan

    1987-01-01

    A kind of copolymer of acrylic acid and vinylpyridine was synthesized and the fluorescent properties of the complexes of the copolymer with Eu3+ or Tb3+ were studied. It was found that the fluorescence intensity of the complexes of the copolymer with Eu3+ was 20 times as high as that of the complexes of polyacrylic acid with Eu3+ and twice as high as that of the complexes of polyvinylpyridine with Eu3+. The effects of the composition of the copolymer and the content of Eu3+ or Tb3+ in the complexes were studied.The fluorescence lifetime of the complexes was measured and it was found that two or more kinds of energy transfer mechanism existed.

  20. Synthesis, Structures and Properties of Three Metal-organic Frameworks Based on 3-(4-((1H-imidazol-1-yl)methyl)phenyl)acrylic Acid

    Three new transition metal complexes based on Ozagrel [Cu(Ozagrel)]n (1), [Zn(Ozagrel)(Cl)]n (2), [Mn2-(Ozagrel)(1,4-ndc)2]·(H2O)n (3), (Ozagrel = 3-(4-((1H-imidazol-1-yl)methyl)phenyl)acrylic acid; 1,4-ndc = 1,4-Naphthalenedicarboxylic acid) have been hydrothermally synthesized and characterized by elemental analyse, IR, TG, PXRD, electrochemical analysis and single crystal X-ray diffraction. X-ray structure analysis reveals that 1 and 3 are 3D coordination polymers, while complex 2 is a two-dimensional network polymer, the 2D layers are further packed into 3D supramolecular architectures that are connected through hydrogen bonds. The electrochemistry of 1-3 was studied by cyclic voltammetry in methanol and water using a glassy carbon working electrode. Also, thermal decomposition process and powder X-ray diffraction of complexes were investigated

  1. Graft copolymerization of acrylic acid to cassava starch--evaluation of the influences of process parameters by an experimental design method.

    Witono, J R; Noordergraaf, I W; Heeres, H J; Janssen, L P B M

    2012-11-01

    The graft copolymerization of cassava starch with acrylic acid was investigated using a free radical initiator system (Fe(2+)/H(2)O(2) redox system) in water. A comprehensive understanding of the important variables and their interaction has been obtained by applying an experimental design method. In this approach, two ('high' and 'low') values of selected variables are considered. Important result parameters are add-on and the grafting efficiency. Out of eight reaction variables, it was found that only temperature, starch concentration and the starch to monomer ratio have a pronounced influence on these response parameters. Moderate reaction temperature (40 °C) and high starch concentration (10%) give relatively good results of add-on and grafting efficiency. A low starch to monomer ratio favors add-on but decreases grafting efficiency. These findings can be used to optimize the production of cassava starch-acrylate copolymers and to gain insight in the process-product property interactions, for various applications. PMID:22944411

  2. Separation of poly(acrylic acid) salts according to topology using capillary electrophoresis in the critical conditions.

    Maniego, Alison R; Ang, Dale; Guillaneuf, Yohann; Lefay, Catherine; Gigmes, Didier; Aldrich-Wright, Janice R; Gaborieau, Marianne; Castignolles, Patrice

    2013-11-01

    Branching was detected in polyacrylates synthesised through radical polymerization via solution-state NMR, while inconsistencies have been reported for the determination of the molar mass of hydrophilic polyacrylates using aqueous-phase and organic-phase size-exclusion chromatography. In this work, poly(sodium acrylate)s, PNaAs, of various topologies were separated for the first time using free-solution capillary electrophoresis (CE). Free-solution CE does not separate the PNaAs by their molar mass, similarly to separations by liquid chromatography in the critical conditions, rather by different topologies (linear, star branched, and hyperbranched). The electrophoretic mobility of PNaAs increases as the degree of branching decreases. Separation is shown to be not only by the topology but also by the end groups as expected for a separation in the critical conditions: replacing a relatively bulky nitroxide end group with hydrogen atom yielded a higher electrophoretic mobility. This novel method, capillary electrophoresis in the critical conditions enabled, for the first time, the separation of hydrophilic polyacrylates according to their topology (branching) and their chain ends. This will allow meaningful and accurate characterization of their branched topologies as well as molar masses and progress in for advanced applications such as drug delivery or flocculation. PMID:23732867

  3. pH-sensitive photocatalytic activities of TiO2/poly(vinyl alcohol)/poly(acrylic acid) composite hydrogels

    The pH-sensitive photocatalytic system was prepared by embedding TiO2 into poly(vinyl alcohol)/poly(acrylic acid) hydrogel. Two different type TiO2/hydrogel composites, such as matrix and nanofiber, were prepared to investigate the morphological effects on the photocatalytic activity. TiO2 was distributed uniformly in the composite hydrogel and kept the original anatase structure without any structural change. The photocatalytic activity of TiO2 was evaluated based on the efficiency of photobleaching of dye. The photobleaching of dye was improved greatly as the pH was changed into basic condition and the larger surface area of hydrogel was available for TiO2 by using nanofiber supports.

  4. pH-sensing properties of cascaded long- and short-period fiber grating with poly acrylic acid/poly allylamine hydrochloride thin-film overlays

    Yang, Ying

    2014-11-01

    Based on coupled-mode theory and transfer matrix method, the mode coupling mechanism and the reflection spectral properties of coated cascaded long- and short-period gratings (CLBG) are discussed. The effects of the thin-film parameters (film refractive index and film thickness) on the reflection spectra of the coated CLBG are simulated. By using electrostatic self-assembly method, poly acrylic acid (PAA) and poly allylamine hydrochloride (PAH) multilayer molecular pH-sensitive thin-films are assembled on the surface of the partial corroded CLBG. When the CLBG coated with PAA/PAH films are used to sense pH values, the resonant wavelengths of the CLBG have almost no shift, whereas the resonance peak reflectivities change with pH values. In addition, the sensitivities of the resonance peak reflectivities responding to pH values are improved by an order of magnitude.

  5. A Novel Route for Preparing Highly Stable Fe3O4 Fluid with Poly(Acrylic Acid) as Phase Transfer Ligand

    Oanh, Vuong Thi Kim; Lam, Tran Dai; Thu, Vu Thi; Lu, Le Trong; Nam, Pham Hong; Tam, Le The; Manh, Do Hung; Phuc, Nguyen Xuan

    2016-08-01

    Highly stable Fe3O4 liquid was synthesized by thermal decomposition using poly(acrylic acid) (PAA) as a phase transfer ligand. The crystalline structure, morphology, and magnetic properties of the as-prepared samples were thoroughly characterized. Results demonstrated that the magnetic Fe3O4 nanomaterial was formed in liquid phase with a spinel single-phase structure, average size of 8-13 nm, and high saturation magnetization (up to 75 emu/g). The PAA-capped Fe3O4 nanoparticles displayed high stability over a wide pH range (from 4 to 7) in 300 mM salt solution. More importantly, the heat-generating capacity of the nanoparticle systems was quantified at a specific absorption rate (SAR) of 70.22 W/g, which is 35% higher than magnetic nanoparticles coated with sodium dodecyl sulfate (SDS). These findings suggest the potential application of PAA-coated magnetic nanoparticles in magnetic hyperthermia.

  6. The use of dielectric spectroscopy for the characterisation of the precipitation of hydrophobically modified poly(acrylic-acid) with divalent barium ions

    Christensen, Peter Vittrup; Keiding, Kristian

    2009-01-01

    The use of dielectric spectroscopy as a monitor for coagulation processes was investigated. Hydrophobically modified poly(acrylic-acid) polymers were used as model macromolecules and coagulated with barium ions. The coagulation process was quantified using a photometric dispersion analyser, thereby...... serving as a point of reference for the dielectric spectroscopy. It was found that the hydrophobic modification increased the dosage of barium needed to obtain complete coagulation, whereas the dosage required to initiate coagulation was lowered. The coagulation of the polymer samples caused the...... relaxation time of the measured dielectric dispersion to increase, and this parameter was found to be a good indicator of the formation of polymer aggregates. The magnitude of the dielectric dispersion decreased as a function of barium dosage, but when coagulation was initiated an increase was observed. The...

  7. Reusable nanocomposite of CoFe2O4/chitosan-graft-poly(acrylic acid) for removal of Ni(II) from aqueous solution

    In this paper, CoFe2O4/chitosan-graft-poly(acrylic acid) (CoFe2O4/CS-graft-PAA) nanocomposites were prepared successfully by coprecipitation of the compounds in alkaline solution and were used for removal of nickel (II) ions from aqueous solution. The sorption rate was affected significantly by the initial concentration of the solution, sorbent amount, and pH value of the solution. Batch experiments were conducted to investigate the adsorption capacity under different initial concentration (ranging from 25 to 150 mg L−1), solution pH (4.1, 5.3, 6.4 and 7.6), and contact time. These nanocomposites can be recycled conveniently from water with the assistance of an external magnet because of their exceptional properties. The prepared nanocomposites were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), x-ray powder diffraction (XRD), and thermogravimetric analysis (TGA). (papers)

  8. Electrospun Poly(acrylonitrile-co-acrylic acid) Nanofibrous Membranes for Catalase Immobilization:Effect of Porphyrin Filling on the Enzyme Activity

    KE Bei-bei; WAN Ling-shu; HUANG Xiao-jun; XU Zhi-kang

    2011-01-01

    Porphyrin-filled nanofibrous membranes were facilely prepared by electrospinning of the mixtures of poly(acryionitrile-co-acrylic acid)(PANCAA) and porphyrins. 5,10,15,20-Tetraphenyiporphyrin(TPP) and its metalloderivatives(ZnTPP and CuTPP) were studied as filling mediators for the immobilization of redox enzyme. Results indicate that the introduction of TPP, ZnTPP and CuTPP improves the retention activity of the immobilized catalase.Among these three porphyrins, the ZnTPP-filled PANCAA nanofibrous membrane exhibits an activity retention of 93%, which is an exciting improvement. This improvement is attributed to both the strong catalase-porphyrin affinity and the possible facilitated electron transfer induced by the porphyrin as evidenced by quartz crystal microbalance (QCM) and fluorescence spectroscopy studies.

  9. Preparation and characterization of electrically conductive composites of poly(vinyl alcohol–g–poly(acrylic acid hydrogels impregnated with polyaniline (PANI

    2008-01-01

    Full Text Available Novel electrically conducting composite materials consisting of poly(aniline (PANI nanoparticles dispersed in a poly(vinyl alcohol (PVA-g-poly(acrylic acid (PAA hydrogels were prepared within the polymer matrix by in situ polymerization of aniline. The conversion yield of aniline into PANI particles was determined gravimetrically while structural confirmation of the synthesized polymer was sought by Fourier Transform Infrared (FTIR, UV-visible analysis and X-ray diffraction (XRD technique. Morphology and dimension of PANI particles embedded into the colored optically semi-transparent hydrogels were evaluated by Scanning Electron Microscopy (SEM analysis. Electrical conductivity of composite hydrogels of different composition was determined by LCR meter while electroactive behavior of composite hydrogels swollen in electrolyte solution was investigated by Effective Bend Angle (EBA measurements.

  10. Surfactant mediated synthesis of poly(acrylic acid) grafted xanthan gum and its efficient role in adsorption of soluble inorganic mercury from water.

    Pal, Abhijit; Majumder, Kunal; Bandyopadhyay, Abhijit

    2016-11-01

    Noble copolymers from xanthan gum (XG) and poly(acrylic acid) (PAA) were synthesised through surfactant mediated graft copolymerization. The copolymers were applied as a biosorbent for inorganic Hg(II) at higher concentration level (300ppm). The copolymers were characterized using different analytical techniques which showed, the grafting principally occurred across the amorphous region of XG. Measurement of zeta potential and hydrodynamic size indicated, the copolymers were strong polyanion and possessed greater hydrodynamic size (almost in all cases) than XG, despite a strong molecular degradation that took place simultaneously during grafting. In the dispersed form, all grades of the copolymer displayed higher adsorption capability than XG, however, the grade with maximum grafting produced the highest efficiency (68.03%). Manipulation produced further improvement in efficiency to 72.17% with the same copolymer after 75min at a pH of 5.0. The allowable biosorbent dose, however, was 1000ppm as determined from the experimental evidences. PMID:27516248

  11. Dynamics of the layer-by-layer assembly of a poly(acrylic acid)-lanthanide complex colloid and poly(diallyldimethyl ammonium).

    Xu, Jiali; Wang, Zhiliang; Wen, Lingang; Zhou, Xianju; Xu, Jian; Yang, Shuguang

    2016-01-21

    Poly(acrylic acid) (PAA) and lanthanide (Ln) ions, such as Ce(3+), Eu(3+), and Tb(3+), were prepared as dispersed complex colloidal particles through three different protocols with rigorous control of the pH value and mixing ratio. The negatively charged PAA-Ln complex particles were layer-by-layer (LbL) assembled with positively charged poly(diallyldimethyl ammonium) (PDDA) to prepare a thin film. The film thickness growth is much quicker than PDDA/PAA film. Due to the incorporation of Ln(3+) ions, the film exhibits fluorescence. During LbL assembly, PDDA-PAA association based on electrostatic force and PAA-Ce association based on coordination are in competition, which leads to the LbL assembly of PDDA and PAA-Ln complex colloidal particles being a complicated dynamic process. PMID:26549538

  12. Sorption of Some Heavy Metal Ions from Aqueous Solutions by Polypropylene Fibers Grafted with Acrylic Acid under the Effect of Gamma Irradiation

    Polypropylene Fibers (PP) grafted with poly acrylic acid (PAAc) were prepared under the effect of gamma irradiation to be used as an adsorbent matrix for Co2+ and Ni2+ ions from aqueous solutions. The different factors which affect the grafting process such as grafting solution, inhibitor concentration, irradiation dose and the monomer concentration were investigated. The grafted PP fibers were characterized by using Fourier-transform infrared (FTIR), X-ray diffraction (XRD), Thermogravimetric analysis (TGA), Differential scanning calorimetery (DSC) and Scanning electron microscopy (SEM). The effect of grafting yield on the mechanical properties of grafted PP fibers was also studied. The different conditions which affect the adsorption capacity of grafted PP fibers towards the metal ions, such as solution pH and contact time were investigated. The adsorption isotherm was studied according to the Langmuir isotherm model. The effect of regeneration cycles on the adsorption capacity of grafted PP fibers was investigated. Keywords: Polypropylene, γ-rays, Metal ions, adsorption.

  13. A Novel Route for Preparing Highly Stable Fe3O4 Fluid with Poly(Acrylic Acid) as Phase Transfer Ligand

    Oanh, Vuong Thi Kim; Lam, Tran Dai; Thu, Vu Thi; Lu, Le Trong; Nam, Pham Hong; Tam, Le The; Manh, Do Hung; Phuc, Nguyen Xuan

    2016-05-01

    Highly stable Fe3O4 liquid was synthesized by thermal decomposition using poly(acrylic acid) (PAA) as a phase transfer ligand. The crystalline structure, morphology, and magnetic properties of the as-prepared samples were thoroughly characterized. Results demonstrated that the magnetic Fe3O4 nanomaterial was formed in liquid phase with a spinel single-phase structure, average size of 8-13 nm, and high saturation magnetization (up to 75 emu/g). The PAA-capped Fe3O4 nanoparticles displayed high stability over a wide pH range (from 4 to 7) in 300 mM salt solution. More importantly, the heat-generating capacity of the nanoparticle systems was quantified at a specific absorption rate (SAR) of 70.22 W/g, which is 35% higher than magnetic nanoparticles coated with sodium dodecyl sulfate (SDS). These findings suggest the potential application of PAA-coated magnetic nanoparticles in magnetic hyperthermia.

  14. Preparation of porous carboxymethyl chitosan grafted poly (acrylic acid) superabsorbent by solvent precipitation and its application as a hemostatic wound dressing.

    Chen, Yu; Zhang, Yong; Wang, Fengju; Meng, Weiwei; Yang, Xinlin; Li, Peng; Jiang, Jianxin; Tan, Huimin; Zheng, Yongfa

    2016-06-01

    The volume phase transition of a hydrogel initiated by shrinking may result in complex patterns on its surface. Based on this unique property of hydrogel, we have developed a novel solvent precipitation method to prepare a kind of novel superabsorbent polymers with excellent hemostatic properties. A porous carboxymethyl chitosan grafted poly (acrylic acid) (CMCTS-g-PAA) superabsorbent polymer was prepared by precipitating CMCTS-g-PAA hydrogel with ethanol. Its potential application in hemostatic wound dressing was investigated. The results indicate that the modified superabsorbent polymer is non-cytotoxic. It showed a high swelling capacity and better hemostatic performance in the treatments of hemorrhage model of ear artery, arteria cruralis and spleen of the New Zealand white rabbit than the unmodified polymer and other commonly used clinic wound dressings. The hemostatic mechanism of the porous CMCTS-g-PAA polymer was also discussed. PMID:27040191

  15. Preparation of poly(polyethylene glycol methacrylate-co-acrylic acid) hydrogels by radiation and their physical properties[Radiation; pH-responsive; Hydrogels; Insulin; Oral delivery

    Park, S.-E.; Nho, Y.-C. E-mail: ycnho@kaeri.re.kr; Kim, H.-I

    2004-02-01

    The pH-responsive copolymer hydrogels were prepared with the monomers of polyethylene glycol methacrylate and acrylic acid based on {gamma}-ray irradiation technique. The gel content of these copolymer hydrogels varied depending on both the composition of monomers and the radiation dose. Maximum gel percent and degree of crosslinking were obtained at the composition of equal amount of comonomers. These copolymer hydrogels did not show any noticeable change in swelling at lower pH range. However they showed an abrupt increase in swelling at higher pH range due to the ionization of carboxyl groups. This pH-responsive swelling behavior was applied for the insulin carrier via oral delivery. Insulin-loaded copolymer hydrogels released most of their insulin in the simulated intestinal fluid which had a pH of 6.8 but not in the simulated gastric fluid which had a pH of 1.2.

  16. Structural changes of polyacids initiated by their neutralization with various alkali metal hydroxides. Diffusion studies in poly(acrylic acid)s.

    Masiak, Michal; Hyk, Wojciech; Stojek, Zbigniew; Ciszkowska, Malgorzata

    2007-09-27

    The changes in the three-dimensional structure of the poly(acrylic acid), PAA, induced by incorporation of various alkali-metal counterions have been evaluated by studying diffusion of an uncharged probe (1,1'-ferrocenedimethanol) in the polymeric media. The studies are supported by the measurements of conductivity and viscosity of the polymeric media. Solutions of linear PAA of four different sizes (molecular weights: 450,000, 750,000, 1,250,000, 4,000,000) were neutralized with hydroxides of alkali metals of group 1 of the periodic table (Li, Na, K, Rb, Cs) to the desired neutralization degree. The transport properties of the obtained polyacrylates were monitored by measuring the changes in the probe diffusion coefficient during the titration of the polyacids. The probe diffusivity was determined from the steady-state current of the probe voltammetric oxidation at disk microelectrodes. Diffusivity of the probe increases with the increase in the degree of neutralization and with the increase in viscosity. It reaches the maximum value at about 60-80% of the polyacid neutralization. The way the probe diffusion coefficients change is similar in all polyacid solutions and gels. The increase in the size of a metal cation causes, in general, an enhancement in the transport of probe molecules. The biggest differences in the probe diffusivities are between lithium and cesium polyacrylates. The differences between the results obtained for cesium and rubidium are not statistically significant due to lack of good precision of the voltammetric measurements. The measurements of the electric conductivity of polyacrylates and the theoretical predictions supplemented the picture of electrostatic interactions between the polyanionic chains and the metal cations of increasing size. In all instances of the PAAs, the viscosity of the solutions rapidly increases in the 0-60% range of neutralization and then becomes constant in the 60-100% region. With the exception of the shortest

  17. Mesoporous silica nanoparticles with bilayer coating of poly(acrylic acid-co-itaconic acid) and human serum albumin (HSA): A pH-sensitive carrier for gemcitabine delivery.

    Pourjavadi, Ali; Tehrani, Zahra Mazaheri

    2016-04-01

    Novel bilayer coated mesoporous silica nanoparticle (MCM-41) based on pH sensitive poly(acrylic acid-co-itaconic acid) and human serum albumin (HSA) was designed for controlled delivery of gemcitabine (anticancer drug) to cancer cells. The shell around the mesoporous silica has bilayer structure. Poly(acrylic acid-co-itaconic acid) was used as pH-sensitive inner shell and human serum albumin, HSA, was used as outer shell. The core-shell structure was formed due to electrostatic interaction between ammonium groups of modified MCM-41 and carboxylate groups of copolymer. Also, the albumin layer was wrapped around the copolymer coated nanoparticle by electrostatic interaction between ammonium groups from protein and carboxylate ions of copolymer shell. Moreover, the maximum release occurred at pH 5.5 (pH of endosomes) because the bilayer shell collapsed at this pH. The drug nanocarrier would be a good candidate for tumor therapy due to its biocompatibility, controlled release and pH responsive behavior. PMID:26838909

  18. Study on acrylic acid bentonite of high amount/poly(sodium acrylate) superabsorbent composite Ⅰ :the preparation process and morphology%高含量丙烯酸膨润土/聚丙烯酸钠高吸水性复合材料的研究Ⅰ:制备工艺与形貌

    付丽华; 彭英知; 韦藤幼; 童张法

    2012-01-01

    Superabsorbent composite of high amount of acrylic acid bentonite/poly(sodium acrylic) was synthesized through solution polymerization with acrylic acid bentonite(ABT) and sodium acrylic and acrylic acid. The morphology of the composite was observed by scanning electron microscope(SEM). The results show that a-crylic acid bentonite is evenly and disorder dispersed in the composite with the sheets of 20-30 nm thickness. The preparation process are optimized. The results are as follows. The amount of ABT, crosslinker and initiator are 30wt% , 0. 3wt% , 1. lwt% of the monomer mass respectively. The total water in the system is 340 % of the monomer mass, the neutralization degree is 64 %). The absorbency of the composite is 1103 g/g in deionized water in the conditions. At the same time, the water retention property of the superabsorbent composite(PAA) is better compared to that of PAA.%通过特殊工艺将丙烯酸膨润土(简称ABT)和丙烯酸钠单体采用溶液聚合法制备出高含量丙烯酸膨润土/聚丙烯酸钠高吸水性复合材料(简称HABT/PAA).SEM考察材料的形貌得知,ABT以20~30nm的尺寸较均匀、无序地分散在聚合物基体中,且与聚合物有很好的相容性.对合成工艺进行了优化得到较优的工艺:ABT用量为单体质量的30%(质量分数),交联剂用量为单体质量的0.3%(质量分数),引发剂用量为单体质量的1.1%(质量分数),体系总水量为单体质量的340%(质量分数),中和度为64%,在此条件下,材料吸附去离子水的能力为1103g/g.同时,HABT/PAA的保水性能较聚丙烯酸钠(PAA)好.

  19. Preparation, properties and biological application of pH-sensitive poly(ethylene oxide) (PEO) hydrogels grafted with acrylic acid(AAc) using gamma-ray irradiation

    pH-sensitive hydrogels were studied as a drug carrier for the protection of insulin from the acidic environment of the stomach before releasing it in the small intestine. In this study, hydrogels based on poly(ethylene oxide) (PEO) networks grafted with acrylic acid (AAc) were prepared via a two-step process. PEO hydrogels were prepared by γ-ray irradiation, and then grafting by AAc monomer onto the PEO hydrogels with the subsequent irradiation (radiation dose: 5-20 kGy, dose rate: 2.15 kGy/h). These grafted hydrogels showed a pH-sensitive swelling behavior. The grafted hydrogels were used as a carrier for the drug delivery systems for the controlled release of insulin. The in vitro drug release behaviors of these hydrogels were examined by quantification analysis with a UV/VIS spectrophotometer. Insulin was loaded into freeze-dried hydrogels (7 mmx3 mmx2.5 mm) and administrated orally to healthy and diabetic Wistar rats. The oral administration of insulin-loaded hydrogels to Wistar rats decreased the blood glucose levels obviously for at least 4 h due to the absorption of insulin in the gastrointestinal tract

  20. Evaluation of scission and crosslinking yields in γ-irradiated poly(acrylic acid) and poly(methacrylic acid) from weight- and Ζ-average molecular weights determined by sedimentation equilibrium

    Weight- and Ζ-average molecular weights, M-barW(D) and M-barΖ(D), of poly(methacrylic acid) (PMMA) and poly(acrylic acid) (PAA) have been determined by sedimentation equilibrium in the ultracentrifuge after various doses D of γ-radiation in vacuum. Relationships between [Mi(0)/Mi(D)-1]/D and D (i=w or Ζ), derived recently by O'Donnell and coworkers, have been used to determine radiation chemical yields for scission and crosslinking of G(S)=6.0, G(X)=0 for PMAA and G(S)=0, G(X)=0.44 for PAA. Allowance was necessary for the effects of COOH decomposition on the average values of the molecular weight and partial specific volume for irradiated PAA. (author)

  1. Application of pH-responsive poly(2-dimethyl-aminoethylmethacrylate)-block-poly(acrylic acid) coatings for the open-tubular capillary electrochromatographic analysis of acidic and basic compounds.

    Sepehrifar, Roshanak; Boysen, Reinhard I; Danylec, Basil; Yang, Yuanzhong; Saito, Kei; Hearn, Milton T W

    2016-04-21

    A new type of stimuli-responsive polymeric (SRP) coating has been prepared for use in open tubular capillary electrochromatography (OT-CEC), by grafting poly(2-dimethylaminoethylmethacrylate)-block-poly(acrylic acid) (PDMAEMA-b-PAA) as a Y-shaped block copolymer with two dissimilar chain compositions onto the inner walls of aminopropyl-modified silica capillaries. The grafting process introduced weakly charged functional groups from the PAA and PDMAEMA, enabling the generation of electroendosmotic flow with magnitude and direction adjustable by changing the pH of the running buffer electrolyte. This stimuli-responsive PDMAEMA-b-PAA block copolymer was found to provide excellent resolution of various acidic and basic compounds, leading to efficient analyte separation. When operated in the OT-CEC mode, separation selectivities could be readily manipulated via differential contributions from chromatographic and electrophoretic mechanisms, simply by changing the pH or the ionic strength of the running buffer electrolyte. PMID:27026608

  2. STUDY ON REGULARITIES OF GRAFT COPOLYMERIZATION OF ACRYLIC ACID ONTO FUNGAL CELL WALL%米根霉细胞壁结构性多糖与丙烯酸接枝共聚反应研究

    张诚; 孟琴; 吕德伟

    2001-01-01

    For the aim of getting macromolecular flocculant,we studied the copolymerization of acrylic acid onto Rhi.oryzae cell wall structural polysaccharide by the initiation of ceric ammonium nitrate.The effect of concentration of initiator and monomer,reaction temperature and reaction time on grafting percentage was investigated.To Rhi.oryzae cell wall structural polysaccharide the maximal grafting percentage of 135.5% was achieved at [Ce+4]=5mmol/L,[AA]=1mol/L,T=60℃,t=3h.Then choosing organic dyes as the flocculated substances,by comparing with the chitosan,polyacrylamide and Rhi.oryzae cell wall structural polysaccharide before grafting,we studied the flocculent capability of Rhi.oryzae cell wall structural polysaccharide after grafting acrylic acid.The grafting product had excellent flocculent effect on basic and neutral dyes.

  3. Characterization of electron beam cured epoxy acrylate

    Epoxy resin has wide application in various industrial fields because of their good mechanical strength, superiority adhesion and low shrinkage etc. And the typical curing method for epoxy resins is thermal and press compaction. However, a curing method was used electron beam process in this study. Epoxy acrylate was fabricated from mixture of epoxy, acrylic acid, tetraphenylporphyrin (TPP) and hydroquinone monomethyl ether (MEHQ) with mole ratios. Then electron beam irradiation effect on the curing of the epoxy acrylate resin was investigated various absorption dose in nitrogen atmospheres at room temperature. The dynamic mechanical and thermal properties of the irradiated epoxy acrylate resins were characterized using dynamic mechanical analysis (DMA) and thermogravimetric analyzer (TGA). And the tensile and flexural strength were measured by an universal tensile machine (UTM)

  4. Obtention and characterization of acrylic acid-i-polyethylene organometallic copolymers with Mo, Fe, Co, Zn, and Ni; Obtencion y caracterizacion de copolimeros organometalicos de acido acrilico-i-polietileno, con Mo, Fe, Co, Zn y Ni

    Dorantes, G.; Urena, F.; Lopez, R. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Lopez, R. [Universidad Autonoma del Estado de Mexico (Mexico)

    1997-07-01

    In this study a graft acrylic acid (AA) in low density polyethylene (PEBD) copolymers were prepared, using as reaction initiator, gamma radiation at different doses. These copolymers were coordinated with molybdenum, cobalt, iron, zinc and nickel. the obtained polymeric materials were characterized by conventional analysis techniques. It was studied the measurement parameter variation of the positron annihilation when they inter activated with this type of materials and so obtaining information about microstructure of these polymers. (Author)

  5. 聚丙烯酸-腐植酸钠复合高吸水树脂的合成研究∗%Study on the Synthesis of Poly Acrylic Acid-sodium Humate Composite Super Absorbent Polymer

    李东芳; 杜明华

    2015-01-01

    该研究采用不除去丙烯酸中阻聚剂及不通氮气的工艺,以丙烯酸、腐植酸钠为原料,通过水溶液聚合法制备了聚丙烯酸-腐植酸钠复合高吸水树脂。研究结果表明:该复合高吸水树脂在丙烯酸的中和度为60%,腐植酸钠用量为1.0g,引发剂过硫酸钾用量为55mg,交联剂N,N′-亚甲基双丙烯酰胺用量为20mg时,吸蒸馏水量最大,为1200 g/g。%The poly acrylic acid-sodium humate composite super absorbent polymer was synthesized by aqueous solution polymerization through the technology of no nitrogen and not removing polymerization inhibitor in acrylic acid. In the synthesis process, acrylic acid and sodium humate were as monomer. The study results showed that when the neutralization degree of acrylic acid was 60%,the dosage of sodium humate was 1. 0g,the dosage of initia-tor( potassium persulfate) was 55mg, and the dosage of crosslinking agent ( N, N′-methylenebisacrylamide) was 20mg,the highest distilled water-absorbing capacity of the composite super absorbent polymer was 1200g/g.

  6. Poly-N-Isopropylacrylamide/acrylic Acid Copolymers for the Generation of Nanostructures at Mica Surfaces and as Hydrophobic Host Systems for the Porin MspA from Mycobacterium smegmatis

    Gamage, Pubudu; Basel, Matthew T.; Lovell, Kimberly; Pokhrel, Megh Raj; Battle, Deletria; Ito, Takashi; Pavlenok, Mikhail; Niederweis, Michael; Stefan H. Bossmann

    2009-01-01

    The work presented here aims at utilizing poly-N-isopropyl-acrylamide/acrylic acid copolymers to create nanostructured layers on mica surfaces by a simple spin-casting procedure. The average composition of the copolymers determined by elemental analysis correlates excellently with the feed composition indicating that the radical polymerization process is statistical. The resulting surfaces were characterized by Atomic Force Microscopy (magnetic AC-mode) at the copolymer/air interface. Postpol...

  7. Multimodal particle size distribution or fractal surface of acrylic acid copolymer nanoparticles: A small-angle X-ray scattering study using direct Fourier and indirect maximum entropy methods

    Mueller, J.J.; Hansen, S; Lukowski, G.; Gast, K.

    1995-01-01

    Acrylic acid copolymers are potential carriers for drug delivery. The surface, surface rugosity and the absolute dimension of the particles are parameters that determine the binding of drugs or detergents, diffusion phenomena at the surface and the distribution of the carrier within the human body. The particle-size distribution and surface rugosity of the particles have been investigated by small-angle X-ray scattering and dynamic light scattering. Direct Fourier transform as well as a new s...

  8. Radiation grafting of pH-sensitive acrylic acid and 4-vinyl pyridine onto nylon-6 using one- and two-step methods

    Acrylic acid (AAc) and 4-vinyl pyridine (4VP) were γ-ray grafted onto nylon-6 (Ny6) films via pre-irradiation oxidative method. These monomers were grafted using a one-step method to render Ny6-g–(AAc/4VP). A two-step or sequential method was used to render (Ny6-g–AAc)-g–4VP. Random copolymer branches were obtained when the grafting was carried out via one-step method using the two monomers together. The two-step method was applied to graft chains of 4VP on both Ny6 substrate and previously grafted AAc chains (Ny6-g–AAc). The two types of binary copolymers synthesized were characterized to determine the amount of grafted polymers, the thermal behavior (DSC and TGA), the surface composition (XPS), and the pH responsiveness. In the two-step process, it is possible to achieve a higher graft yield, better control of the amount of each monomer, good reversibility in the swelling/deswelling process and shorter time to achieve equilibrium swelling. - Highlights: • A new binary graft of 4VP and AAc onto Ny6 films was synthesized by γ-radiation. • The binary grafted material has potential application for heavy ion retention. • The two-step method shows better conditions in swelling and reversibility properties. • Surface distribution of monomers was evaluate by XPS characterization

  9. Radiation grafting of pH-sensitive acrylic acid and 4-vinyl pyridine onto nylon-6 using one- and two-step methods

    Ortega, Alejandra; Alarcón, Darío; Muñoz-Muñoz, Franklin; Garzón-Fontecha, Angélica; Burillo, Guillermina

    2015-04-01

    Acrylic acid (AAc) and 4-vinyl pyridine (4VP) were γ-ray grafted onto nylon-6 (Ny6) films via pre-irradiation oxidative method. These monomers were grafted using a one-step method to render Ny6-g-(AAc/4VP). A two-step or sequential method was used to render (Ny6-g-AAc)-g-4VP. Random copolymer branches were obtained when the grafting was carried out via one-step method using the two monomers together. The two-step method was applied to graft chains of 4VP on both Ny6 substrate and previously grafted AAc chains (Ny6-g-AAc). The two types of binary copolymers synthesized were characterized to determine the amount of grafted polymers, the thermal behavior (DSC and TGA), the surface composition (XPS), and the pH responsiveness. In the two-step process, it is possible to achieve a higher graft yield, better control of the amount of each monomer, good reversibility in the swelling/deswelling process and shorter time to achieve equilibrium swelling.

  10. Synthesis and Characterization of Chemically Cross-Linked Acrylic Acid/Gelatin Hydrogels: Effect of pH and Composition on Swelling and Drug Release

    Syed Majid Hanif Bukhari

    2015-01-01

    Full Text Available This present work was aimed at synthesizing pH-sensitive cross-linked AA/Gelatin hydrogels by free radical polymerization. Ammonium persulfate and ethylene glycol dimethacrylate (EGDMA were used as initiator and as cross-linking agent, respectively. Different feed ratios of acrylic acid, gelatin, and EGDMA were used to investigate the effect of monomer, polymer, and degree of cross-linking on swelling and release pattern of the model drug. The swelling behavior of the hydrogel samples was studied in 0.05 M USP phosphate buffer solutions of various pH values pH 1.2, pH 5.5, pH 6.5, and pH 7.5. The prepared samples were evaluated for porosity and sol-gel fraction analysis. Pheniramine maleate used for allergy treatment was loaded as model drug in selected samples. The release study of the drug was investigated in 0.05 M USP phosphate buffer of varying pH values (1.2, 5.5, and 7.5 for 12 hrs. The release data was fitted to various kinetic models to study the release mechanism. Hydrogels were characterized by Fourier transformed infrared (FTIR spectroscopy which confirmed formation of structure. Surface morphology of unloaded and loaded samples was studied by surface electron microscopy (SEM, which confirmed the distribution of model drug in the gel network.

  11. Measurement of non-DLVO force on a silicon substrate coated with ammonium poly(acrylic acid) using scanning probe microscopy

    Isobe, Toshihiro; Nakano, Yosuke; Kameshima, Yoshikazu; Nakajima, Akira; Okada, Kiyoshi

    2009-07-01

    The repulsive force originating from steric hindrance of polymers in aqueous solvent was investigated using scanning probe microscopy (SPM). The contact angle (CA) of ammonium poly(acrylic acid) (PAA) solution on the Si surface was measured to estimate the state of the Si substrate. Results of CA measurement show that the Si surface was fully covered with PAA at 0.1 mass% in aqueous solution. The interaction force between the Si tip and the wafer was estimated using the SPM force curve mode. The force curve measured in the ion-exchanged purified water showed the typical relation predicted by Derjaguin-Landau-Verway-Overbeek (DLVO) theory. However, the force curve shape in the 0.1 mass% PAA solution was significantly different. Only a repulsive force was observed at less than about 4 nm of separation distance between the Si wafer and cantilever tip. This distance originated from the steric repulsions of PAA adsorbed onto the Si wafer and cantilever tip.

  12. Poly(acrylic acid)-regulated Synthesis of Rod-Like Calcium Carbonate Nanoparticles for Inducing the Osteogenic Differentiation of MC3T3-E1 Cells.

    Yang, Wei; Yao, Chenxue; Cui, Zhengyang; Luo, Dandan; Lee, In-Seop; Yao, Juming; Chen, Cen; Kong, Xiangdong

    2016-01-01

    Calcium carbonate, especially with nanostructure, has been considered as a good candidate material for bone regeneration due to its excellent biodegradability and osteoconductivity. In this study, rod-like calcium carbonate nanoparticles (Rod-CC NPs) with desired water dispersibility were achieved with the regulation of poly (acrylic acid). Characterization results revealed that the Rod-CC NPs had an average length of 240 nm, a width of 90 nm with an average aspect ratio of 2.60 and a negative ζ-potential of -22.25 ± 0.35 mV. The degradation study illustrated the nanoparticles degraded 23% at pH 7.4 and 45% at pH 5.6 in phosphate-buffered saline (PBS) solution within three months. When cultured with MC3T3-E1 cells, the Rod-CC NPs exhibited a positive effect on the proliferation of osteoblast cells. Alkaline phosphatase (ALP) activity assays together with the osteocalcin (OCN) and bone sialoprotein (BSP) expression observations demonstrated the nanoparticles could induce the differentiation of MC3T3-E1 cells. Our study developed well-dispersed rod-like calcium carbonate nanoparticles which have great potential to be used in bone regeneration. PMID:27164090

  13. Chitosan-crosslinked gels prepared by a simultaneously occurring reaction of radiation-induced polymerization and self-bridging of acrylic acid in aqueous solutions

    Chitosan is one of the most interesting natural polymers, in addition to its biodegradability it shows wide biological properties such as antifibrolastic and antimicrobial activities, which verify its biomedical application. Novel Acrylic acid/Chitosan hydrogel was prepared by means of γ-irradiation as a clean source for initiation, and crosslinking. The nature of the AAc/CS gel and the effect of the presence of chitosan on the behavior of AAc were characterized. The effect of pH on the degree of swelling of different gels and time course swelling studies show the effect of presence of chitosan and its molecular weight on the swelling of the gels. DSC and TGA were used to study the effect of the presence of chitosan on the thermal behavior of PAAc. It was found that chitosan change thermal behavior of AAc. These results support our assumption for the formation of crosslinking between PAAc and CS chains via polyelectrolyte complex formation, attributed to the high affinity between CS and AAc, accompanied by homopolymerization and self-bridging. This crosslinking increase with CS molecular weight increasing and affect the thermal behavior of PAAc. (author)

  14. Study of the adhesive properties versus stability/aging of hernia repair meshes after deposition of RF activated plasma polymerized acrylic acid coating.

    Rivolo, Paola; Nisticò, Roberto; Barone, Fabrizio; Faga, Maria Giulia; Duraccio, Donatella; Martorana, Selanna; Ricciardi, Serena; Magnacca, Giuliana

    2016-08-01

    In order to confer adhesive properties to commercial polypropylene (PP) meshes, a surface plasma-induced deposition of poly-(acrylic acid) (PPAA) is performed. Once biomaterials were functionalized, different post-deposition treatments (i.e. water washing and/or thermal treatments) were investigated with the aim of monitoring the coating degradation (and therefore the loss of adhesion) after 3months of aging in both humid/oxidant (air) and inert (nitrogen) atmospheres. A wide physicochemical characterization was carried out in order to evaluate the functionalization effectiveness and the adhesive coating homogeneity by means of static water drop shape analysis and several spectroscopies (namely, FTIR, UV-Visible and X-ray Photoemission Spectroscopy). The modification of the adhesion properties after post-deposition treatments as well as aging under different storage atmospheres were investigated by means of Atomic Force Microscopy (AFM) used in Force/Distance (F/D) mode. This technique confirms itself as a powerful tool for unveiling the surface adhesion capacity as well as the homogeneity of the functional coatings along the fibers. Results obtained evidenced that post-deposition treatments are mandatory in order to remove all oligomers produced during the plasma-treatment, whereas aging tests evidenced that these devices can be simply stored in presence of air for at least three months without a meaningful degradation of the original properties. PMID:27157754

  15. “Stable-on-the-Table” Biosensors: Hemoglobin-Poly (Acrylic Acid Nanogel BioElectrodes with High Thermal Stability and Enhanced Electroactivity

    Ananta Ghimire

    2015-09-01

    Full Text Available In our efforts toward producing environmentally responsible but highly stable bioelectrodes with high electroactivities, we report here a simple, inexpensive, autoclavable high sensitivity biosensor based on enzyme-polymer nanogels. Met-hemoglobin (Hb is stabilized by wrapping it in high molecular weight poly(acrylic acid (PAA, MW 450k, and the resulting nanogels abbreviated as Hb-PAA-450k, withstood exposure to high temperatures for extended periods under steam sterilization conditions (122 °C, 10 min, 17–20 psi without loss of Hb structure or its peroxidase-like activities. The bioelectrodes prepared by coating Hb-PAA-450k nanogels on glassy carbon showed well-defined quasi-reversible redox peaks at −0.279 and −0.334 V in cyclic voltammetry (CV and retained >95% electroactivity after storing for 14 days at room temperature. Similarly, the bioelectrode showed ~90% retention in electrochemical properties after autoclaving under steam sterilization conditions. The ultra stable bioelectrode was used to detect hydrogen peroxide and demonstrated an excellent detection limit of 0.5 μM, the best among the Hb-based electrochemical biosensors. This is the first electrochemical demonstration of steam-sterilizable, storable, modular bioelectrode that undergoes reversible-thermal denaturation and retains electroactivity for protein based electrochemical applications.

  16. The effect of concentration of acrylic acid, dose rates and temperature on preirradiated graft of natural rubber-based thermoplastic elastomer

    Grafting acrylic acid (AAc) onto thermoplastic elastomer (TE) films, a kind of product from natural rubber latex block-grafted by methyl methacrylate monomer was investigated. The preirradiated dose from a gamma Co-60 source for TE at 75 kGy was considered to be useful. Significant concentration of AAc aqueous solution for the grafting process is 20% (vol%). Dose rate of about 3.4 kGy/h is more effective for the graft. The temperature of around 90 deg. C is suitable for obtaining a higher degree of graft. It is observed that the rate of grafting of AAc onto TE is proportional to 0.48 power of dose rate and 1.9 power of AAc concentration. The rate of grafting can be expressed as Rg=k·I0.48·M1.9. On the other hand, overall activation energy of the graft is estimated about 7.2 Kcal/mol. The FTIR spectrum analysis of TE and TE-g-AAc films was proceeded

  17. Radiation grafting of pH and thermosensitive N-isopropylacrylamide and acrylic acid onto PTFE films by two-steps process

    Polytetrafluoroethylene (PTFE) was grafted (g) with acrylic acid (AAc) by γ-ray pre-irradiation method to get PTFE-g-AAc films, then N-isopropylacrylamide (NIPAAm) was grafted onto PTFE-g-AAc films with γ-ray to get (PTFE-g-AAc)-g-NIPAAm. PTFE films were irradiated in air at a dose rate of 3.0 kGy h-1 and different radiation dose. The irradiated films were placed in glass ampoules, which contained aqueous solutions with different monomer concentration (AAc), and then they were heated at different temperatures and reaction time. NIPAAm onto PTFE-g-AAc was carried out with the same procedure with monomer concentration of 1 mol L-1. The thermosensitivity of the samples was defined and calculated as the ratio of the grafted samples swelling at 28 and 35 oC, and pH sensitivity defined as the ratio of the grafted samples swelling at pH 2 and 8

  18. Fabrication of magnetic hydroxypropyl cellulose-g-poly(acrylic acid) porous spheres via Pickering high internal phase emulsion for removal of Cu(2+) and Cd(2.).

    Zhu, Yongfeng; Zheng, Yian; Zong, Li; Wang, Feng; Wang, Aiqin

    2016-09-20

    A series of magnetic hydroxypropyl cellulose-g-poly(acrylic acid) porous spheres were prepared via O/W Pickering high internal phase emulsions (HIPEs) integrated precipitation polymerization. The structure and composition of modified Fe3O4 and porous structures were characterized by TEM, XRD, TGA and SEM. The results indicated that the silanized Fe3O4 can influence greatly the pore structure of magnetic porous sphere in addition to non-negligible impacts of the proportion of mixed solvent and co-surfactant. The adsorption experiment demonstrated that the adsorption equilibrium can be reached within 40min and the maximal adsorption capacity was 300.00mg/g for Cd(2+) and 242.72mg/g for Cu(2+), suggesting its fast adsorption kinetics and high adsorption capacity. After five adsorption-desorption cycles, no significant changes in the adsorption capacity were observed, suggesting its excellent reusability. The magnetic porous sphere can be easily separated from the solution and then find its potential as a recyclable material for highly efficient removal of heavy metals. PMID:27261748

  19. Preparation of superabsorbent by graft copolymerization of acrylic acid onto corn starch using K2S2O8 and rare earths as initiators

    BAI Yong-ping; LI Wei-dong; FENG Li-qun; ZHAO chao

    2008-01-01

    K2S2O8 and rare earths (RE) were used as initiators to prepare superabsorbents by graft copolymeri-zation of acrylic acid (AA) onto corn starch. The effects of monomer concentration, initiator K2S2O8 concentra-tion, cross-linker concentration, reaction temperature and the concentration ratio of RE and K2S2O8 on the graft copolymerization were studied in terms of the water absorption capacity of superabsorbents. Results indicate that the optimum conditions obtained for the grafting of AA onto 5g starch are as follows: AA of 75. 773 g/L, K2S2O8 of 0.437 g/L, RE of 0.874 g/L, cross-linker of 0.381 g/L and temperature of 70℃. The maximum water absorption capacity obtained is 740 g/g. The new method of graft polymerization is easily proceeded and controlled. The graft copolymers were characterized by infra-red spectroscopy, scanning electron microscopy and TG. Results characterized by IR and SEM give strong evidence for grafting of AA onto corn starch, and those characterized by TG reveal that the grafting of AA improves the thermostability of corn starch.

  20. Poly(acrylic acid-regulated Synthesis of Rod-Like Calcium Carbonate Nanoparticles for Inducing the Osteogenic Differentiation of MC3T3-E1 Cells

    Wei Yang

    2016-05-01

    Full Text Available Calcium carbonate, especially with nanostructure, has been considered as a good candidate material for bone regeneration due to its excellent biodegradability and osteoconductivity. In this study, rod-like calcium carbonate nanoparticles (Rod-CC NPs with desired water dispersibility were achieved with the regulation of poly (acrylic acid. Characterization results revealed that the Rod-CC NPs had an average length of 240 nm, a width of 90 nm with an average aspect ratio of 2.60 and a negative ζ-potential of −22.25 ± 0.35 mV. The degradation study illustrated the nanoparticles degraded 23% at pH 7.4 and 45% at pH 5.6 in phosphate-buffered saline (PBS solution within three months. When cultured with MC3T3-E1 cells, the Rod-CC NPs exhibited a positive effect on the proliferation of osteoblast cells. Alkaline phosphatase (ALP activity assays together with the osteocalcin (OCN and bone sialoprotein (BSP expression observations demonstrated the nanoparticles could induce the differentiation of MC3T3-E1 cells. Our study developed well-dispersed rod-like calcium carbonate nanoparticles which have great potential to be used in bone regeneration.

  1. "Stable-on-the-Table" Biosensors: Hemoglobin-Poly (Acrylic Acid) Nanogel BioElectrodes with High Thermal Stability and Enhanced Electroactivity.

    Ghimire, Ananta; Zore, Omkar V; Thilakarathne, Vindya K; Briand, Victoria A; Lenehan, Patrick J; Lei, Yu; Kasi, Rajeswari M; Kumar, Challa V

    2015-01-01

    In our efforts toward producing environmentally responsible but highly stable bioelectrodes with high electroactivities, we report here a simple, inexpensive, autoclavable high sensitivity biosensor based on enzyme-polymer nanogels. Met-hemoglobin (Hb) is stabilized by wrapping it in high molecular weight poly(acrylic acid) (PAA, M(W) 450k), and the resulting nanogels abbreviated as Hb-PAA-450k, withstood exposure to high temperatures for extended periods under steam sterilization conditions (122 °C, 10 min, 17-20 psi) without loss of Hb structure or its peroxidase-like activities. The bioelectrodes prepared by coating Hb-PAA-450k nanogels on glassy carbon showed well-defined quasi-reversible redox peaks at -0.279 and -0.334 V in cyclic voltammetry (CV) and retained >95% electroactivity after storing for 14 days at room temperature. Similarly, the bioelectrode showed ~90% retention in electrochemical properties after autoclaving under steam sterilization conditions. The ultra stable bioelectrode was used to detect hydrogen peroxide and demonstrated an excellent detection limit of 0.5 μM, the best among the Hb-based electrochemical biosensors. This is the first electrochemical demonstration of steam-sterilizable, storable, modular bioelectrode that undergoes reversible-thermal denaturation and retains electroactivity for protein based electrochemical applications. PMID:26393601

  2. Ultrasonic Velocity, Viscosity and Refractive Index Investigation on Interacting Blend Solutions of PAA (Poly Acrylic Acid) and PVA (Poly Vinyl Alcohol) in Solvent DMSO (Di methyl Sulphoxide)

    Nagamani, Chakrala

    2010-11-01

    The present study provides a great insight into the major new research areas like Plasma research (which is yielding a greater understanding of the universe) and Nano Technology Research (which provides many practical uses like Drug Delivery System). The Ultrasonic Velocities, Viscosities and Refractive indices of Poly (Acrylic Acid) and Poly (Vinyl Alcohol) blends in DMSO solutions have been measured over a wide range of composition, concentration and at different temperatures. The variation of Ultrasonic Velocity, derived acoustical parameters, adiabatic compressibility, acoustic impedance, Rao number, molar compressibility and relaxation strength with composition of blend solution was found not linear. This non-linearity has been attributed to incompatibility in conformity with the earlier findings. This behavior was confirmed by Viscometric and interaction parameters studies, as well as by investigation of Refractive index studies. These investigations offer an entirely new and simple approach to the study of the compatibility of polymer blends which is in general obtained by sophisticated techniques of thermal dynamic mechanical and electron microscopic analysis.

  3. Sono-assisted photocatalytic degradation of styrene-acrylic acid copolymer in aqueous media with nano titania particles and kinetic studies.

    Saien, J; Delavari, H; Solymani, A R

    2010-05-15

    The ultrasonic irradiation (28 kHz, 50 W) in pre-cavitations regime was employed to enhance the degradation rate of styrene-acrylic acid copolymer in aqueous media with nano titania photocatalyst particles. A stainless steel cylindrical sono-photo reactor with capacity of about 1.25 L, equipped with a UV lamp (250 W) was used. The influence of operational parameters, i.e. catalyst concentration, pH and temperature was studied and the role of active species was also distinguished. For an initial substrate concentration of 30 mg L(-1), under mild applied conditions of 30 mg L(-1) of photocatalyst, 25 degrees C and natural pH, a degradation and mineralization conversion of 96% and 91%, respectively, was achieved using sono-assisted photocatalysis process in about only 60 min. These efficiencies are much higher than those obtained with only photocatalysis process. Meanwhile, the threshold of cavitations was found corresponded to catalyst concentration of about 70 mg L(-1). Kinetic studies based on Langmuir-Hinshelwood and power law models in addition to the results from radical scavenger usage revealed that for sono-assisted process, the substrate undergoes degradation mainly via electron-hole redox on the surface of titania particles. It is while for the only photocatalysis process, the reaction proceeds via hydroxyl radicals in the solution bulk. PMID:20092940

  4. Phase-transfer behavior of cross-linked poly(acrylic acid) particles prepared by dispersion polymerization from ionic liquid to water.

    Minami, Hideto; Mizuta, Yusuke; Kimura, Akira

    2012-02-01

    The phase-transfer behavior of poly(acrylic acid) (PAA) particles from the hydrophobic ionic liquid N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium bis(trifluoromethanesulfonyl)amide phase to the water phase in the particle state, which we reported previously, was examined in more detail. PAA particles were prepared in the ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide ([Bmim][TFSA]) and the organic solvent chloroform and were extracted. The transfer of PAA particles to water in the particle state was also observed in [Bmim][TFSA] systems. In contrast, the transfer phenomenon was not observed in the chloroform system. It was clarified that water/oil interfacial tension γ(wo) is an important parameter in the extraction of PAA in the particle state from the viewpoint of free energy. When the cationic surfactant tetradecyltrimethylammonium bromide, aqueous solution was used as the extraction medium, the PAA particles were extracted in the particle state from chloroform to water, in which γ(wo) became as low as that of the ionic liquid. This suggests that the phase-transfer phenomenon of PAA particles in the particle state was induced by the ionic liquid's unique property of low interfacial tension with water despite its high hydrophobic character. PMID:22235893

  5. Poly (N-vinyl-2-pyrrolidone-co-acrylic acid): Comparing of Traditional Heating and Microwave-Assisted Free Radical Polymerization

    In organic chemistry microwave irradiation has become a common heat source and the use of microwave irradiation is also increasingly studied for polymerization reactions. Polymers have been synthesized at long reaction times by classical thermal methods. In contrast, microwave-assisted polymer synthesis is a well-known and most useful method, which is requiring shorter reaction times. In this study, our aims are to compare THPS and MAPS methods between themselves, and investigate the effect of temperature in MAPS method at different parameters such as reaction times, weight average molecular weight (Mw), polydispersity index (PDI), hydrodynamic radius (Rh), intrinsic and Mark Houwink equation constant (a) of copolymers, viscosity Firstly we synthesized N-vinyl-2-pyrrolidone-acrylic acid copolymers (P(VP-co-AA)) both with traditional heating polymer synthesis (THPS) and microwave-assisted polymer synthesis (MAPS) method comparatively in this study. Secondly, to research temperature effect on MAPS method in addition to microwave irradiation power, polymer synthesis at 40 degree C, 50 degree C and 80 degree C were tried. For analyzing of copolymers Fourier Transform Infrared (FT-IR) spectroscopy and Gel Permeation Chromatography (GPC) system with four detectors were used. (author)

  6. Photocurable bioactive bone cement based on hydroxyethyl methacrylate-poly(acrylic/maleic) acid resin and mesoporous sol gel-derived bioactive glass.

    Hesaraki, S

    2016-06-01

    This paper reports on strong and bioactive bone cement based on ternary bioactive SiO2-CaO-P2O5 glass particles and a photocurable resin comprising hydroxyethyl methacrylate (HEMA) and poly(acrylic/maleic) acid. The as-cured composite represented a compressive strength of about 95 MPa but it weakened during soaking in simulated body fluid, SBF, qua its compressive strength reached to about 20 MPa after immersing for 30 days. Biodegradability of the composite was confirmed by reducing its initial weight (~32%) as well as decreasing the molecular weight of early cured resin during the soaking procedure. The composite exhibited in vitro calcium phosphate precipitation in the form of nanosized carbonated hydroxyapatite, which indicates its bone bonding ability. Proliferation of calvarium-derived newborn rat osteoblasts seeded on top of the composite was observed during incubation at 37 °C, meanwhile, an adequate cell supporting ability was found. Consequently, it seems that the produced composite is an appropriate alternative for bone defect injuries, because of its good cell responses, high compressive strength and ongoing biodegradability, though more in vivo experiments are essential to confirm this assumption. PMID:27040248

  7. pH-responsive controlled-release fertilizer with water retention via atom transfer radical polymerization of acrylic acid on mussel-inspired initiator.

    Ma, Zhi-yuan; Jia, Xin; Zhang, Guo-xiang; Hu, Jia-mei; Zhang, Xiu-lan; Liu, Zhi-yong; Wang, He-yun; Zhou, Feng

    2013-06-12

    This work reports a polydopamine-graft-poly(acrylic acid) (Pdop-g-PAA)-coated controlled-release multi-element compound fertilizer with water-retention function by a combination of mussel-inspired chemistry and surface-initiated atom transfer radical polymerization (SI-ATRP) techniques for the first time. The morphology and composition of the products were characterized by transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), gel permeation chromatography (GPC), and inductively coupled plasma (ICP) emission spectrometry. The results revealed that the stimuli-responsive layer formed by a Pdop inner layer and a PAA outer corona exhibit outstanding selective permeability to charged nutrients and the release rate of encapsulated elements can be tailored by the pH values. At low pH, the Pdop-g-PAA layer can reduce nutrient loss, and at high pH, the coating restrains transportation of negative nutrients but favors the release of cations. Moreover, PAA brushes provide good water-retention property. This Pdop-graft-polymer brushes coating will be effective and promising in the research and development of multi-functional controlled-release fertilizer. PMID:23692274

  8. Silicone/Acrylate Copolymers

    Dennis, W. E.

    1982-01-01

    Two-step process forms silicone/acrylate copolymers. Resulting acrylate functional fluid is reacted with other ingredients to produce copolymer. Films of polymer were formed by simply pouring or spraying mixture and allowing solvent to evaporate. Films showed good weatherability. Durable, clear polymer films protect photovoltaic cells.

  9. Radiation induced copolymerization of binary monomers system(styrene/acrylic acid) and its application in removal of some heavy metals and dyes from aquatic solutions

    Radiation-induced coploymerization of binary monomer system styrene/acrylic acid (Sty/AAc) using direct radiation technique has been investigated. The appropriate reaction conditions such as solvent, commonomer concentration, commonomer composition and irradiation dose at which the coplymerization process was carried out successfully were selected. The effect of different parameters on the conversion percent of the commonmer into coplomer was studied by gravimetric method. It was found that, using methanol/distilled water as a cosolvent with composition 80/20 wt% enhanced the copolymerization process. The conversion (%) of the commonomer was increased with increasing radiation dose. Some properties of the coplymer such as wate uptake, thermal stability, surface topography were investigated. The improvement in such properties of the prepared coplymers was observed which makes possible uses in some practical applications such as in the removal of some heavy metals and dyes from wastewater. the prepared copolymer has good chemical and thermal stability where as the styrene content lead to increase the swelling behaviour. It was found that the maximum metal uptake by the coplymer is ordered in the sequence of Bp2+>Cu2+>Ni2+. The possibility of the removal of three classes of dyes from aqueous solutions; namely wegocet yellow 4GL (direct yellow 44), congo red (diect red 28). Remacryl blue 3G (basic blue3) and xylene blue *acid blue 7 was studied. It could be concluded that the Sty/AAc copolymer with composition 20/80 wt % can be used as a contrilled water retainer for carrying of some substance in aquatic fields involving environmental treatments. Also, it could be concluded that the most important parameter affecting the swelling behaviour and characteristic of the prepared copolymer are the type of conversion due to chemical treatment, the pH of the medium and coonstituents of the prepared copolymer

  10. Palm oil based polyols for acrylated polyurethane production

    Palm oil becomes important renewable resources for the production of polyols for the polyurethane manufacturing industry. The main raw materials used for the production of acrylated polyurethane are polyols, isocyanates and hydroxyl terminated acrylate compounds. In these studies, polyurethane based natural polymer (palm oil), i.e., POBUA (Palm Oil Based Urethane Acrylate) were prepared from three different types of palm oil based polyols i.e., epoxidised palm oil (EPOP), palm oil oleic acid and refined, bleached and deodorized (RBD) palm olein based polyols. The performances of these three acrylated polyurethanes when used for coatings and adhesives were determined and compared with each other. (Author)

  11. Development of heterogenized catalyst systems for the synthesis of acrylic acid derivatives from carbon dioxide and ethylene

    Prasetyo, Eko

    2015-01-01

    Use of CO2 as chemical feedstock represents one of the most sustainable ways for carbon recycling, generating high value products. Current industrial practices include the manufacture of urea, organic (poly)carbonates, and salicylic acid. CO2 can also be used to produce CO-rich syngas, which can be further processed to olefins, aldehydes, alcohols, or synthetic fuel via the Fischer-Tropsch process. Direct carboxylation with CO2 yielding carbonates, carbamates, carboxylates, or lactones is of ...

  12. One-step routes from di- and triblock copolymer precursors to hydrophilic nanoporous poly(acrylic acid)-b-polystyrene

    Guo, Fengxiao; Jankova Atanasova, Katja; Schulte, Lars;

    2008-01-01

    the same time part of the nanoporosity, and PDMS was quantitatively etched to provide additional nanoporosity. Both the deprotection of the PtBA block and the etching of PDMS were realized by one-step operations using either anhydrous hydrogen fluoride (HF) or trifluoroacetic acid (TFA). The finding......, and scanning electron microscopy. In contact with water, all the prepared nanoporous polymers showed spontaneous water uptake close to the amounts expected from the precursor block copolymer compositions....

  13. The use of natural rubber-based material for the preparation of radiation-curable resin. I. The reaction of epoxidised natural rubbers of low molecular weight with acrylic acid

    A synthesis method for the preparation of a new radiation-curable resin based on natural rubber has been established. The method was based on the reaction between epoxidised natural rubbers (ENR) of low molecular weight, i.e. Mn 0f 5,800 to 82,000, with acrylic acid in the presence of a catalyst and an inhibitor. Two grades of ENR namely ENR-25 and ENR-50 corresponding to 25 and 50 mole % epoxidation levels, respectively were used. The acrylation was carried out at temperatures between 95-105 degree C and was monitored by the measurements of the acid value of the reaction mixture as the reaction proceeded. It was confirmed by IR spectroscopic technique that the reaction occurred through the ring opening of the epoxide group of ENR. As a result, the new resin contains radiation-curable acrylate groups as well as hydroxyl groups on its main chain. When formulated with benzophenone, it solidified upon with UV light

  14. Properties and mechanisms of drug release from matrix tablets containing poly(ethylene oxide) and poly(acrylic acid) as release retardants.

    Zhang, Feng; Meng, Fan; Lubach, Joseph; Koleng, Joseph; Watson, N A

    2016-08-01

    The interactions between poly(ethylene oxide) (PEO) and poly(acrylic acid) (PAA) in aqueous medium at pH 6.8 were investigated in the current study. We have also studied the effect of interpolymer interactions and various formulation variables, including the molecular weight of PEO, the ratio between PEO and PAA, the crystallinity of PEO, and the presence of an acidifying agent, on the release of theophylline from matrix tablets containing both PEO and PAA as release retardants. At pH 6.8, the synergy in solution viscosity between PEO and PAA as the result of ion-dipole interaction was observed in this study. The release of theophylline from the matrix tablets containing physical mixtures of PEO and PAA was found to be a function of dissolution medium pH because of the pH-dependent interactions between these two polymers. Because of the formation of water insoluble interpolymer complex between PEO and PAA in aqueous medium at pH below 4.0, the release of theophylline was independent of PEO molecular weight and was controlled by Fickian diffusion mechanism in 0.01N hydrochloric acid solution. In comparison, the drug release was a function of PEO molecular weight and followed the anomalous transport mechanism in phosphate buffer pH 6.8. The presence of PAA exerted opposite effects on the release of theophylline in phosphate buffer pH 6.8. In one aspect, theophylline release was accelerated because the erosion of PAA was much faster than that of PEO at pH6.8. On the opposite aspect, theophylline release was slowed down because of the formation of insoluble complex inside the gel layer as the result of the acidic microenvironment induced by PAA, and the increase in the viscosity of the gel layer as the result of the synergy between PEO and PAA. These two opposite effects offset each other. As a result, the release of theophylline remained statistically the same even when 75% PEO in the formulation was replaced with PAA. In phosphate buffer pH 6.8, the release of

  15. Optical limiting response of multi-walled carbon nanotube-phthalocyanine nanocomposite in solution and when in poly (acrylic acid)

    Sekhosana, Kutloano Edward; Nyokong, Tebello

    2016-08-01

    Bis{23-(3,4-di-yloxybenzoic acid)-(2(3), 9(10), 16(17), 23(24)-(hexakis-pyridin-3-yloxy phthalocyaninato)} dineodymium (III) acetate (3) is linked to amino-functionalized multi-walled carbon nanotubes (MWCNT) to form 3-MWCNT. Z-scan technique was employed to experimentally determine the nonlinear absorption coefficient from the open-aperture data. The limiting threshold values as low as 0.045 J cm-2 were found in solution. The conjugate (3-MWCNT) gave better optical limiting behavior than complex 3 alone.

  16. He-Ne laser protection barrier by means of poly (Tetrafluoroethylene-Perfluoro vinyl Ether) grafted by acrylic acid complexed with Cu(II)

    Appropriate eye and skin protection is a prerequisite for the safe operation of He-Ne laser in industrial and laboratory environments. In the present paper, measurement of the optical parameters of poly (tetrafluoroethylene-perfluorovinyl ether) grafted by acrylic acid and complexed with Cu(II) are reported. He-Ne laser beam radiation on wavelength of 632.8 nm and power 12.5mW was used. Transmittance and reflectance spectra and refractive index dispersion are presented. The study showed that the material has a protective level 4. Environmental conditions like thermal and fading processes were tested. This suggested that the material preserves its protective features as a protective eye and skin barriers of protective level 4. This was applied for occupational working time up to 8 h, temperature up to 50 degree C and for a time equal 74 days after laser irradiation. Radiation protection from laser sources has attracted a great deal of attention for long time because of their importance for human body. Intensive progress in lasers, optical communications, and data storage has challenged scientists to achieve perfection in optical components. These challenges have resulted in an active development of a wide variety of unconventional optical elements (Hariharan, 1996 and Efimov et al., 2002). Alexandrite solid state lasers with a wavelength of about 755 nm are frequently used in the field of medicine (Schirmarcher and Sutter, 2001). For removing tattoos, the Q-switched versions with impulse widths of several ten nanoseconds are an ideal instrument to keep the thermal stress of the patient's skin at low level. He-Ne laser is one of the most commonly used visible light lasers

  17. Radiation-grafting of thermo- and pH-responsive poly(N-vinylcaprolactam-co-acrylic acid) onto silicone rubber and polypropylene films for biomedical purposes

    Ferraz, Caroline C.; Varca, Gustavo H. C.; Ruiz, Juan-Carlos; Lopes, Patricia S.; Mathor, Monica B.; Lugão, Ademar B.; Bucio, Emilio

    2014-04-01

    This work focuses on the effects of gamma-ray irradiation conditions on the stimuli-responsiveness of polypropylene (PP) films and silicone (SR) rubber substrates grafted with N-vinylcaprolactam (NVCL) and acrylic acid (AAc). PP films and SR rubber were modified by simultaneous polymerization and grafting of NVCL and AAc, using pre-irradiation oxidative method at a dose rate of 12.23 kGy h-1 and doses ranging from 5 to 70 kGy. NVCL and AAc solutions (1/1, v/v) at 50% monomer concentration (v/v) in toluene were added to the sample substrates, degassed, sealed and heated at 60 and 70 °C for 12 h. After grafting, the samples were soaked in ethanol and distilled water for 24 h successively, followed by drying under vacuum. Samples were characterized by FTIR-ATR, DSC and swelling measurements. Critical points (pH critical or LCST) of grafts were obtained in a pH-environment (pH ranges from 2.2 to 9) and in a thermo-environment (temperature ranges from 22 to 50 °C). Cytotoxicity evaluation was performed using fibroblast BALB/c 3T3 cells. The relationship between NVCL-co-AAc grafting and radiation dose was different for each substrate, PP and SR. At 50% NVCL/AAc concentration in toluene, grafting values were higher for SR than for PP. Despite the fact that PP-g-(NVCL-co-AAc) membrane presented a cytotoxic profile at the highest experimental concentration assayed, cytotoxicity evaluation revealed noncytotoxic profiles for the membranes synthesized highlighting their applications for biomedical purposes.

  18. Physicochemical properties of pH-controlled polyion complex (PIC) micelles of poly(acrylic acid)-based double hydrophilic block copolymers and various polyamines.

    Warnant, J; Marcotte, N; Reboul, J; Layrac, G; Aqil, A; Jerôme, C; Lerner, D A; Gérardin, C

    2012-05-01

    The physicochemical properties of polyion complex (PIC) micelles were investigated in order to characterize the cores constituted of electrostatic complexes of two oppositely charged polyelectrolytes. The pH-sensitive micelles were obtained with double hydrophilic block copolymers containing a poly(acrylic acid) block linked to a modified poly(ethylene oxide) block and various polyamines (polylysine, linear and branched polyethyleneimine, polyvinylpyridine, and polyallylamine). The pH range of micellization in which both components are ionized was determined for each polyamine. The resulting PIC micelles were characterized using dynamic light scattering and small-angle X-ray scattering experiments (SAXS). The PIC micelles presented a core-corona nanostructure with variable polymer density contrasts between the core and the corona, as revealed by the analysis of the SAXS curves. It was shown that PIC micelle cores constituted by polyacrylate chains and polyamines were more or less dense depending on the nature of the polyamine. It was also determined that the density of the cores of the PIC micelles depended strongly on the nature of the polyamine. These homogeneous cores were surrounded by a large hairy corona of hydrated polyethylene oxide block chains. Auramine O (AO) was successfully entrapped in the PIC micelles, and its fluorescence properties were used to get more insight on the core properties. Fluorescence data confirmed that the cores of such micelles are quite compact and that their microviscosity depended on the nature of the polyamine. The results obtained on these core-shell micelles allow contemplating a wide range of applications in which the AO probe would be replaced by various cationic drugs or other similarly charged species to form drug nanocarriers or new functional nanodevices. PMID:22453608

  19. Unusually Stable Hysteresis in the pH-Response of Poly(Acrylic Acid) Brushes Confined within Nanoporous Block Polymer Thin Films.

    Weidman, Jacob L; Mulvenna, Ryan A; Boudouris, Bryan W; Phillip, William A

    2016-06-01

    Stimuli-responsive soft materials are a highly studied field due to their wide-ranging applications; however, only a small group of these materials display hysteretic responses to stimuli. Moreover, previous reports of this behavior have typically shown it to be short-lived. In this work, poly(acrylic acid) (PAA) chains at extremely high grafting densities and confined in nanoscale pores displayed a unique long-lived hysteretic behavior caused by their ability to form a metastable hydrogen bond network. Hydraulic permeability measurements demonstrated that the conformation of the PAA chains exhibited a hysteretic dependence on pH, where different effective pore diameters arose in a pH range of 3 to 8, as determined by the pH of the previous environment. Further studies using Fourier transform infrared (FTIR) spectroscopy demonstrated that the fraction of ionized PAA moieties depended on the thin film history; this was corroborated by metal adsorption capacity, which demonstrated the same pH dependence. This hysteresis was shown to be persistent, enduring for days, in a manner unlike most other systems. The hypothesis that hydrogen bonding among PAA units contributed to the hysteretic behavior was supported by experiments with a urea solution, which disrupted the metastable hydrogen bonded state of PAA toward its ionized state. The ability of PAA to hydrogen bond within these confined pores results in a stable and tunable hysteresis not previously observed in homopolymer materials. An enhanced understanding of the polymer chemistry and physics governing this hysteresis gives insight into the design and manipulation of next-generation sensors and gating materials in nanoscale applications. PMID:27172428

  20. Thin ZnO nanocomposite poly(styrene-acrylic acid) films on Si and SiO2 surfaces

    The properties and formation of self-assembled ZnO nanoclusters using polystyrene-based diblock copolymers are reported. The polystyrene-polyacrylic acid copolymer consisting of a majority block (polystyrene) and a minority block (polyacrylic acid) with a block number average molecular weight ratio of 16,500/4500 and a block repeat unit ratio of 159/63 was used in order to obtain self-assembly due to microphase separation with spherical morphology. The self-assembly of the inorganic nanoparticles was achieved at room temperature in the liquid phase using a ZnCl2 precursor dopant attached to the minority block, and both dry and wet chemical processing techniques compatible with semiconductor manufacturing were developed in order to convert the ZnCl2 precursor into ZnO. The polymer films were applied by standard spin-on photolithographic techniques on Si wafers with and without thermally grown SiO2 surface films. A study by X-ray photoelectron spectroscopy (XPS) confirmed the conversion of the ZnCl2 dopant precursor into ZnO within the copolymer matrix, and atomic force microscopy (AFM) showed the spherical morphology of the resultant ZnO nanoclusters. Conversion of the precursor into ZnO was achieved both by a wet chemical treatment and by developing a new dry chemical treatment process based on ozone exposure. The study showed that the dry treatment has better stability and shorter conversion exposure times on the Si surfaces than the wet treatment approach, resulting in lateral size distribution between 250 and 350 nm and height distribution between 80 and 130 nm for the ZnO nanoclusters

  1. Hydrophilic surface modification of acrylate-based biomaterials.

    Arnal-Pastor, M; Comín-Cebrián, S; Martínez-Ramos, C; Monleón Pradas, M; Vallés-Lluch, A

    2016-04-01

    Acrylic polymers have proved to be excellent with regard to cell adhesion, colonization and survival, in vitro and in vivo. Highly ordered and regular pore structures thereof can be produced with the help of polyamide templates, which are removed with nitric acid. This treatment converts a fraction of the ethyl acrylate side groups into acrylic acid, turning poly(ethyl acrylate) scaffolds into a more hydrophilic and pH-sensitive substrate, while its good biological performance remains intact. To quantify the extent of such a modification, and be able to characterize the degree of hydrophilicity of poly(ethyl acrylate), poly(ethyl acrylate) was treated with acid for different times (four, nine and 17 days), and compared with poly(acrylic acid) and a 90/10%wt. EA/AAc copolymer (P(EA-co-AAc)). The biological performance was also assessed for samples immersed in acid up to four days and the copolymer, and it was found that the incorporation of acidic units on the material surface was not prejudicial for cells. This surface modification of 3D porous hydrophobic scaffolds makes easier the wetting with culture medium and aqueous solutions in general, and thus represents an advantage in the manageability of the scaffolds. PMID:26767395

  2. Development of radiation curable surface coating based on soybean oil. part I. preparation and characterization of acrylated oil

    An epoxy acrylate was synthesized from epoxidized soybean oil (ESOL) by using acrylic acid monomer. Triethyl amine (TEA) and hydroquinone were used as catalyst and inhibitor respectively. The epoxidized soybean oil acrylate (ESOLA) is done by introducing acrylic acid into oxirane groups of the epoxidized oil (ESOL). This reaction was confirmed by analytical data in terms of oxirane oxygen content, acid value, viscosity and spectroscopically analysis

  3. Analytical investigations of poly(acrylic acid) coatings electrodeposited on titanium-based implants: a versatile approach to biocompatibility enhancement.

    De Giglio, E; Cometa, S; Cioffi, N; Torsi, L; Sabbatini, L

    2007-12-01

    A polyacrylic acid film was synthesized on titanium substrates from aqueous solutions via an electroreductive process for the first time. This work was done in order to develop a versatile coating for titanium-based orthopaedic implants that acts as both an effective bioactive surface and an effective anti-corrosion barrier. The chemical structure of the PAA coating was investigated by X-ray photoelectron spectroscopy (XPS). Scanning electron microscopy (SEM) was employed to evaluate the effect of annealing treatment on the morphology of the coatings in terms of their uniformity and porosity. Inductively coupled plasma mass spectrometry was used to measure ion concentrations in ion release tests performed on Ti-6Al-4V sheets modified with PAA coatings (annealed and unannealed). Results indicate that the annealing process produces coatings that possess considerable anti-corrosion performance. Moreover, the availability and the reactivity of the surface carboxylic groups were exploited in order to graft biological molecules onto the PAA-modified titanium implants. The feasibility of the grafting reaction was tested using a single aminoacid residue. A fluorinated aminoacid was selected, and the grafting reaction was monitored both by XPS, using fluorine as a marker element, and via quartz crystal microbalance (QCM) measurements. The success of the grafting reaction opens the door to the synthesis of a wide variety of PAA-based coatings that are functionalized with selected bioactive molecules and promote positive reactions with the biological system interfacing the implant while considerably reducing ion release into surrounding tissues. PMID:17516054

  4. Surface functionalisation of polypropylene hernia-repair meshes by RF-activated plasma polymerisation of acrylic acid and silver nanoparticles

    Graphical abstract: - Highlights: • Polypropylene meshes for hernioplasty were surface functionalised via plasma-polymerisation to confer adhesive properties. • Subsequently, silver nanoparticles were loaded to add antibacterial activity. • Materials were physico-chemical characterised and adhesive properties evaluated. - Abstract: Hernia diseases are among the most common and diffuse causes of surgical interventions. Unfortunately, still nowadays there are different phenomena which can cause the hernioplasty failure, for instance post-operative prostheses displacements and proliferation of bacteria in the surgical site. In order to limit these problems, commercial polypropylene (PP) and polypropylene/Teflon (PP/PTFE) bi-material meshes were surface functionalised to confer adhesive properties (and therefore reduce undesired displacements) using polyacrylic acid synthesized by plasma polymerisation (PPAA). A broad physico-chemical and morphological characterisation was carried out and adhesion properties were investigated by means of atomic force microscopy (AFM) used in force/distance (F/D) mode. Once biomedical devices surface was functionalised by PPAA coating, metallic silver nanoparticles (AgNPs) with antimicrobial properties were synthesised and loaded onto the polymeric prostheses. The effect of the PPAA, containing carboxylic functionalities, adhesive coating towards AgNPs loading capacity was verified by means of X-ray photoelectron spectroscopy (XPS). Preliminary measurement of the Ag loaded amount and release in water were also investigated via inductively coupled plasma atomic emission spectroscopy (ICP-AES). Promising results were obtained for the functionalised biomaterials, encouraging future in vitro and in vivo tests

  5. Surface functionalisation of polypropylene hernia-repair meshes by RF-activated plasma polymerisation of acrylic acid and silver nanoparticles

    Nisticò, Roberto, E-mail: roberto.nistico@unito.it [University of Torino, Department of Chemistry and NIS Research Centre, Via P. Giuria 7, 10125 Torino (Italy); Rosellini, Andrea [University of Torino, Department of Chemistry and NIS Research Centre, Via P. Giuria 7, 10125 Torino (Italy); Rivolo, Paola [Politecnico di Torino, Dipartimento di Scienza Applicata e Tecnologia, C.so Duca degli Abruzzi 24, 10129 Torino (Italy); Faga, Maria Giulia [CNR-IMAMOTER, Strada delle Cacce 73, 10135 Torino (Italy); Lamberti, Roberta; Martorana, Selanna [Herniamesh S.r.l., Via F.lli Meliga 1/C, 10034 Chivasso (Italy); Castellino, Micaela [Center for Space Human Robotics, Istituto Italiano di Tecnologia, Corso Trento 21, 10129 Torino (Italy); Virga, Alessandro; Mandracci, Pietro [Politecnico di Torino, Dipartimento di Scienza Applicata e Tecnologia, C.so Duca degli Abruzzi 24, 10129 Torino (Italy); Malandrino, Mery; Magnacca, Giuliana [University of Torino, Department of Chemistry and NIS Research Centre, Via P. Giuria 7, 10125 Torino (Italy)

    2015-02-15

    Graphical abstract: - Highlights: • Polypropylene meshes for hernioplasty were surface functionalised via plasma-polymerisation to confer adhesive properties. • Subsequently, silver nanoparticles were loaded to add antibacterial activity. • Materials were physico-chemical characterised and adhesive properties evaluated. - Abstract: Hernia diseases are among the most common and diffuse causes of surgical interventions. Unfortunately, still nowadays there are different phenomena which can cause the hernioplasty failure, for instance post-operative prostheses displacements and proliferation of bacteria in the surgical site. In order to limit these problems, commercial polypropylene (PP) and polypropylene/Teflon (PP/PTFE) bi-material meshes were surface functionalised to confer adhesive properties (and therefore reduce undesired displacements) using polyacrylic acid synthesized by plasma polymerisation (PPAA). A broad physico-chemical and morphological characterisation was carried out and adhesion properties were investigated by means of atomic force microscopy (AFM) used in force/distance (F/D) mode. Once biomedical devices surface was functionalised by PPAA coating, metallic silver nanoparticles (AgNPs) with antimicrobial properties were synthesised and loaded onto the polymeric prostheses. The effect of the PPAA, containing carboxylic functionalities, adhesive coating towards AgNPs loading capacity was verified by means of X-ray photoelectron spectroscopy (XPS). Preliminary measurement of the Ag loaded amount and release in water were also investigated via inductively coupled plasma atomic emission spectroscopy (ICP-AES). Promising results were obtained for the functionalised biomaterials, encouraging future in vitro and in vivo tests.

  6. The development of epoxidised palm oil acrylate (EPOLA) and its applications

    The topics are discussed briefly. Acrylated palm oil is prepared through acrylation process, whereby, acrylic acid is introduced into oxirane group of the EPOP (epoxidised palm oil products), EPOLA (epoxidised palm oil products acrylate) was found curable when subjected to UV (ultrviolet) light giving soft coatings. EPOLA is used as radiation curable filler/sealer, radiation curable pressure sensitive adhesives and satisfactorily be coated on wood substrates (rubberwood parquets)

  7. Novel azo-peresters radical initiators used for the synthesis of acrylic pressure-sensitive adhesives

    2008-04-01

    Full Text Available Acrylic pressure-sensitive adhesives (PSA based on two monomers: 2-ethylhexyl acrylate and acrylic acid were synthesized in organic solvent ethyl acetate using AIBN (2, 2'-azo-diisobutyronitrile and new synthesized azo-peresters as radical initiators. After polymerization the viscosity, molecular weight and polydispersity of synthesized acrylic PSA were evaluated. The novel synthesized radical azo-perester initiators were synthesized, isolated and compared with industrial predominant usable azo-initiator AIBN.

  8. Rapid removal of copper with magnetic poly-acrylic weak acid resin: Quantitative role of bead radius on ion exchange

    Highlights: • The equilibrium adsorption amount of Cu2+ onto NDMC was 267.2 mg/g. • Initial adsorption rate of NDMC was 4 and 8 times that of C106 and IRC-748. • External surface area was determined to be the key factor in rate-controlling. • Adsorption amount onto NDMC was not influenced by Na+ concentration. • 0.01 mM HCl solution could effectively desorb Cu2+. - Abstract: A novel magnetic weak acid resin NDMC was self-synthesized for the removal of Cu2+ from aqueous solutions. NDMC showed superior properties on the removal of Cu2+ compared to commercial resins C106 and IRC-748, which was deeply investigated by adsorption isotherms and kinetic tests. The equilibrium adsorption amount of Cu2+ onto NDMC (267.2 mg/g) was almost twice as large as that onto IRC-748 (120.0 mg/g). The adsorption kinetics of Cu2+ onto the three resins fitted well with the pseudo-second-order equation. The initial adsorption rate h of NDMC was about 4 times that of C106 and nearly 8 times that of IRC-748 at the initial concentration of 500 mg/L. External surface area was determined to be the key factor in rate-controlling by further analyzing the adsorption thermodynamics, kinetics parameters and physicochemical properties of the resins. NDMC resin with the smallest bead radius possessed the largest external surface and therefore exhibited the fastest kinetics. The adsorption amount of Cu2+ onto NDMC was not influenced as the concentration of Na+ increased from 1.0 to 10.0 mM/L. Dilute HCl solution could effectively desorb Cu2+. NDMC demonstrated high stability during 10 adsorption/desorption cycles, showing great potential in the rapid removal of Cu2+ from wastewater

  9. Matrix tablets based on thiolated poly(acrylic acid): pH-dependent variation in disintegration and mucoadhesion.

    Guggi, Davide; Marschütz, Michaela K; Bernkop-Schnürch, Andreas

    2004-04-15

    This study examined the influence of the pH on the mucoadhesive and cohesive properties of polyarcylic acid (PAA) and thiolated PAA. The pH of PAA (molecular mass: 450 kDa) and of a corresponding PAA-cysteine conjugate was adjusted to 3, 4, 5, 6, 7 and 8. The amount of immobilised thiol groups and disulfide bonds was determined via Ellman's reagent. Tablets were compressed out of each pH-batch of both thiolated and unmodified PAA and the swelling behaviour, the disintegration time and the mucoadhesiveness were evaluated. The amount of thiol/disulfide groups per gram thiolated PAA of pH 3 and pH 8 was determined to be 332 +/- 94 micromol and 162 +/- 46 micromol, respectively. The thiolated PAA tablets displayed a minimum four-fold higher water uptake compared to unmodified PAA tablets. A faster and higher water uptake of both polymer types was observed above pH 5. Thiolated polymer tablets showed a 3-20-fold more prolonged disintegration time than unmodified PAA tablets. The cohesiveness of PAA-cysteine conjugate increased at higher pH, whereas the unmodified PAA behaved inversely. A 3-7-fold stronger mucoadhesiveness was observed for the PAA-cysteine conjugate tablets compared to unmodified PAA tablets. For both thiolated and unmodified polymer the mucoadhesiveness was 2-4-fold enhanced below pH 5. The difference in mucoadhesion between the two polymer types was most pronounced at these lower pH values. In this study substantial information regarding the pH-dependence of mucoadhesion and cohesion of unmodified polyacrylates and of thiolated polyacrylates is provided, representing helpful basic information for an ameliorated deployment of these polymers. PMID:15072786

  10. Preparation and characterization of hybrid pH-sensitive hydrogels of chitosan-co-acrylic acid for controlled release of verapamil.

    Ranjha, Nazar M; Ayub, Gohar; Naseem, Shahzad; Ansari, Muhammad Tayyab

    2010-10-01

    In the present work crosslinked hydrogels based on chitosan (CS) and acrylic acid (AA) were prepared by free radical polymerization with various feed compositions using N,N methylenebisacrylamide (MBA) as crosslinking agent. Benzoyl peroxide was used as catalyst. Fourier transform infrared spectra (FTIR) confirmed the formation of the crosslinked hydrogels. This hydrogel is formed due to electrostatic interaction between cationic groups in CS and anionic groups in AA. Prepared hydrogels were used for dynamic and equilibrium swelling studies. For swelling behavior, effect of pH, polymeric and monomeric compositions and degree of crosslinking were investigated. Swelling studies were performed in USP phosphate buffer solutions of varying pH 1.2, 5.5, 6.5 and 7.5. Results showed that swelling increased by increasing AA contents in structure of hydrogels in solutions of higher pH values. This is due to the presence of more carboxylic groups available for ionization. On the other hand by increasing the chitosan content swelling increased in a solution of acidic pH, but this swelling was not significant and it is due to ionization of amine groups present in the structure of hydrogel. Swelling decreased with increase in crosslinking ratio owing to tighter hydrogel structure. Porosity and sol-gel fraction were also measured. With increase in CS and AA contents porosity and gel fraction increased, whereas by increasing MBA content porosity decreased and gel fraction increased. Furthermore, diffusion coefficient (D) and the network parameters i.e., the average molecular weight between crosslinks (M(c)), polymer volume fraction in swollen state (V(2s)), number of repeating units between crosslinks (M(r)) and crosslinking density (q) were calculated using Flory-Rehner theory. Selected samples were loaded with a model drug verapamil. Release of verapamil depends on the ratios of CS/AA, degree of crosslinking and pH of the medium. The release mechanisms were studied by fitting

  11. Rapid removal of copper with magnetic poly-acrylic weak acid resin: Quantitative role of bead radius on ion exchange

    Fu, Lichun; Shuang, Chendong; Liu, Fuqiang, E-mail: jogia@163.com; Li, Aimin, E-mail: liaimin@nju.edu.cn; Li, Yan; Zhou, Yang; Song, Haiou

    2014-05-01

    Highlights: • The equilibrium adsorption amount of Cu{sup 2+} onto NDMC was 267.2 mg/g. • Initial adsorption rate of NDMC was 4 and 8 times that of C106 and IRC-748. • External surface area was determined to be the key factor in rate-controlling. • Adsorption amount onto NDMC was not influenced by Na{sup +} concentration. • 0.01 mM HCl solution could effectively desorb Cu{sup 2+}. - Abstract: A novel magnetic weak acid resin NDMC was self-synthesized for the removal of Cu{sup 2+} from aqueous solutions. NDMC showed superior properties on the removal of Cu{sup 2+} compared to commercial resins C106 and IRC-748, which was deeply investigated by adsorption isotherms and kinetic tests. The equilibrium adsorption amount of Cu{sup 2+} onto NDMC (267.2 mg/g) was almost twice as large as that onto IRC-748 (120.0 mg/g). The adsorption kinetics of Cu{sup 2+} onto the three resins fitted well with the pseudo-second-order equation. The initial adsorption rate h of NDMC was about 4 times that of C106 and nearly 8 times that of IRC-748 at the initial concentration of 500 mg/L. External surface area was determined to be the key factor in rate-controlling by further analyzing the adsorption thermodynamics, kinetics parameters and physicochemical properties of the resins. NDMC resin with the smallest bead radius possessed the largest external surface and therefore exhibited the fastest kinetics. The adsorption amount of Cu{sup 2+} onto NDMC was not influenced as the concentration of Na{sup +} increased from 1.0 to 10.0 mM/L. Dilute HCl solution could effectively desorb Cu{sup 2+}. NDMC demonstrated high stability during 10 adsorption/desorption cycles, showing great potential in the rapid removal of Cu{sup 2+} from wastewater.

  12. Analysis and Testing of Bisphenol A—Free Bio-Based Tannin Epoxy-Acrylic Adhesives

    Shayesteh Jahanshahi; Antonio Pizzi; Ali Abdulkhani; Alireza Shakeri

    2016-01-01

    A tannin-based epoxy acrylate resin was prepared from glycidyl ether tannin (GET) and acrylic acid. The influence of the reaction condition for producing tannin epoxy acrylate was studied by FT-MIR, 13C-NMR, MALDI-TOF spectroscopy and shear strength. The best reaction conditions for producing tannin epoxy acrylate resin without bisphenol A was by reaction between GET and acrylic acid in the presence of a catalyst and hydroquinone at 95 °C for 12 h. FT-MIR, 13C-NMR and MALDI-TOF analysis have...

  13. 腐植酸钾/丙烯酸型保水剂的合成及性能研究%Synthesis and performance of potassium humate/acrylic acid water-retaining agent

    魏友华; 顾铭茜; 季燕; 陈洪龄

    2013-01-01

    以腐植酸钾(KHA)与丙烯酸(AA)为原料,N,N-亚甲基双丙烯酰胺为交联剂,过K2SO4为引发剂,进行水溶液聚合,制备得到腐植酸钾/丙烯酸高吸水性保水树脂.研究了反应物比例、反应温度、交联剂、引发剂用量、中和度等因素对产物性能的影响.考察了产物的热稳定性、保水性能、耐电解质和重复使用性能.结果表明,树脂最大吸水率为609g·g-1,耐盐性良好,50℃环境温度下9h保水树脂仍有94.2%的保水率.%Potassium humate/acrylic acid water retention resin was prepared from potassium humate and acrylic acid by aqueous polymerization with the crosslinking agent of N, N-methylene-bis-acrylamide and the initiator of potassium persulfate. The effect of reactant ratio, reaction temperature, the amount of cross-linking agent and initiator, and the neutralization degree were investigated. In addition, thermal stability, water retention and reuse ability of the products were studied. Results show that the maximum water absorption ability of potassium humate/acrylic acid superabsorbent resin was 609g·g-1 for distilled water. At the environment temperature 50℃, the water retention resin still have 94.2% of the water retention rate after 9 hour.

  14. Poly-N-Isopropylacrylamide/acrylic Acid Copolymers for the Generation of Nanostructures at Mica Surfaces and as Hydrophobic Host Systems for the Porin MspA from Mycobacterium smegmatis.

    Gamage, Pubudu; Basel, Matthew T; Lovell, Kimberly; Pokhrel, Megh Raj; Battle, Deletria; Ito, Takashi; Pavlenok, Mikhail; Niederweis, Michael; Bossmann, Stefan H

    2009-09-17

    The work presented here aims at utilizing poly-N-isopropyl-acrylamide/acrylic acid copolymers to create nanostructured layers on mica surfaces by a simple spin-casting procedure. The average composition of the copolymers determined by elemental analysis correlates excellently with the feed composition indicating that the radical polymerization process is statistical. The resulting surfaces were characterized by Atomic Force Microscopy (magnetic AC-mode) at the copolymer/air interface. Postpolymerization modification of the acrylic acid functions with perfluoro-octyl-iodide decreased the tendency towards spontaneous formation of nanopores. Crosslinking of individual polymer chains permitted the generation of ultraflat layers, which hosted the mycobacterial channel protein MspA, without compromising its channel function. The comparison of copolymers of very similar chemical composition that have been prepared by living radical polymerization and classic radical polymerization indicated that differences in polydispersity played only a minor role when poly-N-isopropyl-acrylamide/acrylic acid copolymers were spincast, but a major role when copolymers featuring the strongly hydrophobic perfluoro-octyl-labels were used. The mean pore diameters were 23.8+/-4.4 nm for P[(NIPAM)(95.5)-co-(AA)(4.5)] (PDI (polydispersity index)=1.55) and 21.8+/-4.2 nm for P[(NIPAM)(95.3)-co-(AA)(4.7)] (PDI=1.25). The depth of the nanopores was approx. 4 nm. When depositing P[(NIPAM)(95)-co-(AA)(2.8)-AAC(8)F(17 2.2)] (PDI=1.29) on Mica, the resulting mean pore diameter was 35.8+/-7.1 nm, with a depth of only 2 nm. PMID:20161351

  15. Effect of styrene and methyl methacrylate comonomers in ethyl acrylate/methacrylic acid latex on particle alkali-swellability, film formation and thickening with associative thickeners

    Šňupárek, J.; Quadrat, Otakar; Horský, Jiří

    2005-01-01

    Roč. 54, č. 2 (2005), s. 99-103. ISSN 0300-9440 R&D Projects: GA ČR(CZ) GA104/02/1360 Institutional research plan: CEZ:AV0Z40500505 Keywords : acrylic latices * alkali-swellable latex particles * hydroplasticization Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.535, year: 2005

  16. Multifunctional electroactive electrospun nanofiber structures from water solution blends of PVA/ODA–MMT and poly(maleic acid-alt-acrylic acid): effects of Ag, organoclay, structural rearrangement and NaOH doping factors

    Şimşek, Murat; Rzayev, Zakir M. O.; Bunyatova, Ulviya

    2016-06-01

    Novel multifunctional colloidal polymer nanofiber electrolytes were fabricated by green reactive electrospinning nanotechnology from various water solution/dispersed blends of poly (vinyl alcohol-co-vinyl acetate) (PVA)/octadecyl amine-montmorillonite (ODA–MMT) as matrix polymer nanocomposite and poly(maleic acid-alt-acrylic acid) (poly(MAc-alt-AA) and/or its Ag-carrying complex as partner copolymers. Polymer nanofiber electrolytes were characterized using FTIR, XRD, thermal (DSC, TGA–DTG), SEM, and electrical analysis methods. Effects of partner copolymers, organoclay, in situ generated silver nanoparticles (AgNPs), and annealing procedure on physical and chemical properties of polymer composite nanofibers were investigated. The electrical properties (resistance, conductivity, activation energy) of nanofibers with/without NaOH doping agent were also evaluated. This work presented a structural rearrangement of nanofiber mats by annealing via decarboxylation of anhydride units with the formation of new conjugated double bond sites onto partner copolymer main chains. It was also found that the semiconductor behaviors of nanofiber structures were essentially improved with increasing temperature and fraction of partner copolymers as well as presence of organoclay and AgNPs in nanofiber composite.

  17. Thermo- and pH-sensitive gel membranes based on poly-(acryloyl- L-proline methyl ester)- graft-poly(acrylic acid) for selective permeation of metal ions

    Hasegawa, Shin; Ohashi, Hitoshi; Maekawa, Yasunari; Katakai, Ryoichi; Yoshida, Masaru

    2005-04-01

    Thermo- and pH-responsive gel membranes were synthesized by γ-ray grafting of pH-responsive poly(acrylic acid) (AAc) onto thermo-responsive polymer gel of acryloyl- L-proline methyl ester (A-ProOMe). The gel membranes of poly(A-ProOMe) with 15 mol% graft chains of AAc exhibited both thermo- and pH-responses. Under the condition (pH 6.0, 30°C) in which the thermo-sensitive unit shrinks and the pH-sensitive unit swells, the selective permeation of Li ion over Co and Ni ions can be achieved.

  18. Synthesis and Characterization of Acrylamide and/or Acrylic Acid Grafted onto Corn Starch bv Irradiation%淀粉-丙烯酸-丙烯酰胺三元接枝物的制备及性质研究

    郭军; 黄劲松; 杜先锋

    2011-01-01

    在60Co间歇式共辐射条件下探讨了淀粉与丙烯酸和丙烯酰胺流变相态的接枝共聚反应;采用FTIR和SEM对接枝产物共聚物进行了结构表征;考察了丙烯酰胺和丙烯酸盐单体的配比、原料配比、辐射剂量等因素对聚合物吸水率、耐盐性等的影响.结果表明,在没有添加任何化学引发剂的情况下可以得到较高耐盐性和高吸水速率的淀粉-丙烯酸-丙烯酰胺共聚物,克服了传统生产方法中耐盐性低、吸水速度慢、高污染、高耗能等问题.%The grafting of acrylamide and/or acrylic acid onto starch by 60Co radiation as an initiator was studied in conditions of intermittent This copolymerization allowed for measurement of important parameters, including the glucose monomer-to-starch ratio and the water absorption of the graft copolymer in salt solutions. The acrylamide-to-acrylic acid ratio, were measured at the radiation dose used in kGy. The graft-copolymerization reaction mechanism and morphology of the copolymer were investigated using FTIR scanning electron microscopy. The effects of the stuff-proportion, radiation does, starch pasting, neutralization degree of acrylic acid, radiation does-rate on the graft copolymerization reaction and absorption capacity of high water were investigated. The results showed that the grafting of acrylic acid on starch could be carried out successfully by 60Co radiation without any chemic initiator. Overcome the traditional production methods with low salt tolerance, slowly water absorption, pollution, high-energy consumption and other problems.

  19. Synthesis and characterization of chitosan-graft-poly(acrylic acid)/rice husk ash hydrogels composites; Sintese e caracterizacao de hidrogeis compositos de cinza da casca de arroz e quitosana enxertada com poli(acido acrilico)

    Rodrigues, Francisco H.A. [Universidade Estadual Vale do Acarau - UVA, Sobral, CE (Brazil); Lopes, Gabriel V.; Pereira, Antonio G.B.; Fajardo, Andre R.; Muniz, Edvani C. [Universidade Estadual de Maringa - UEM, PR (Brazil)

    2011-07-01

    According to environmental concerns, super absorbent hydrogel composites were synthesized based on rice husk ash (RHA), an industrial waste, and Chitosan-graft-poly(acrylic acid). The WAXS and FTIR data confirmed the syntheses of hydrogel composites. The effect of crystalline or amorphous RHA on water uptake was investigated. It was found that the RHA in crystalline form induces higher water capacity (W{sub eq}) of composites hydrogels due to the fact that the intra-interactions among silanol groups on RHA make available new sites in the polymer matrix, which could interact to water. (author)

  20. Pyrolysis of carbonaceous particles and properties of Carbonaceous-g-Poly (acrylic acid-co-acrylamide superabsorbent polymer for agricultural applications

    Ghazali S.

    2016-01-01

    Full Text Available Utilisation of fertilizer and water are very important in determining the production of agriculture nowadays. The excessive use of fertilizer in plantation somehow could leads to environmental pollution. The present study reported a synthesis of controlled release water retention (CRWR fertilizer coating with superabsorbent polymer (SAPs. Superabsorbent polymer (SAPs are polymers that have ability to absorb and retain large amounts of water relative to their own mass. The presence of coating layer of SAPs on fertilizer granules was believed could reduce excessive used of fertilizer by controlling their dissolution rates and also reduce the environmental pollution. In this study, the effect on the addition of carbonaceous filler in SAPs on the water absorbency was also be compared with control SAPs (without carbonaceous particles. In this study, the carbonaceous filler were obtained from pyrolysis process of empty fruit bunch (EFB biomass. The synthesized of SAPs and carbonaceous-SAPs were carried out via solution polymerization technique by using monomer of poly(acrylic acid (AA, acrylamide (AM, cross linker, methylene bisacrylamide (MBA and initiator, ammonium peroxodisulfate (APS that partially neutralized with sodium hydroxide (NaOH. The CRWR fertilizer was later be prepared by coated the fertilizer granule with SAPs and carbonaceous-SAPs. The water absorbency, morphology and the bonding formation of both CRWR fertilizer were investigated by using tea-beg method, Scanning Electron Microscopy (SEM and Fourier Transform Infrared Spectrophotometer (FTIR, respectively. Moreover, the water retention studies was conducted in order to investigate the efficiency of CRWR coated with SAP and carbonaceous-SAP in retaining the water content in different soil (organic and top soil. Based on the results, the CRWR fertilizer that was coated with carbonaceous-SAP had higher water absorbency value than the CRWR fertilizer without carbonaceous-SAP. Meanwhile

  1. Radiation-grafting of thermo- and pH-responsive poly(N-vinylcaprolactam-co-acrylic acid) onto silicone rubber and polypropylene films for biomedical purposes

    This work focuses on the effects of gamma-ray irradiation conditions on the stimuli-responsiveness of polypropylene (PP) films and silicone (SR) rubber substrates grafted with N-vinylcaprolactam (NVCL) and acrylic acid (AAc). PP films and SR rubber were modified by simultaneous polymerization and grafting of NVCL and AAc, using pre-irradiation oxidative method at a dose rate of 12.23 kGy h−1 and doses ranging from 5 to 70 kGy. NVCL and AAc solutions (1/1, v/v) at 50% monomer concentration (v/v) in toluene were added to the sample substrates, degassed, sealed and heated at 60 and 70 °C for 12 h. After grafting, the samples were soaked in ethanol and distilled water for 24 h successively, followed by drying under vacuum. Samples were characterized by FTIR-ATR, DSC and swelling measurements. Critical points (pH critical or LCST) of grafts were obtained in a pH-environment (pH ranges from 2.2 to 9) and in a thermo-environment (temperature ranges from 22 to 50 °C). Cytotoxicity evaluation was performed using fibroblast BALB/c 3T3 cells. The relationship between NVCL-co-AAc grafting and radiation dose was different for each substrate, PP and SR. At 50% NVCL/AAc concentration in toluene, grafting values were higher for SR than for PP. Despite the fact that PP-g-(NVCL-co-AAc) membrane presented a cytotoxic profile at the highest experimental concentration assayed, cytotoxicity evaluation revealed noncytotoxic profiles for the membranes synthesized highlighting their applications for biomedical purposes. - Highlights: • Graft copolymers synthesized by simultaneous polymerization and grafting under distinct conditions: irradiation and grafting reactions. • Simultaneous grafting of NVCL-co-AAc from PP and SR achieved via a γ-ray pre-irradiation method. • Grafted NVCL-co-AAc onto PP or SR substrates led to thermo and pH stimuli responsive properties

  2. Acrylic vessel cleaning tests

    The acrylic vessel as constructed is dirty. The dirt includes blue tape, Al tape, grease pencil, gemak, the glue or residue form these tapes, finger prints and dust of an unknown composition but probably mostly acrylic dust. This dirt has to be removed and once removed, the vessel has to be kept clean or at least to be easily cleanable at some future stage when access becomes much more difficult. The authors report on the results of a series of tests designed: (a) to prepare typical dirty samples of acrylic; (b) to remove dirt stuck to the acrylic surface; and (c) to measure the optical quality and Th concentration after cleaning. Specifications of the vessel call for very low levels of Th which could come from tape residues, the grease pencil, or other sources of dirt. This report does not address the concerns of how to keep the vessel clean after an initial cleaning and during the removal of the scaffolding. Alconox is recommended as the cleaner of choice. This acrylic vessel will be used in the Sudbury Neutrino Observatory

  3. Acrylic purification and coatings

    ,

    2012-01-01

    Radon (Rn) and its decay daughters are a well-known source of background in direct WIMP detection experiments, as either a Rn decay daughter or an alpha particle emitted from a thin inner surface layer of a detector could produce a WIMP-like signal. Different surface treatment and cleaning techniques have been employed in the past to remove this type of contamination. A new method of dealing with the problem has been proposed and used for a prototype acrylic DEAP-1 detector. Inner surfaces of the detector were coated with a layer of ultra pure acrylic, meant to shield the active volume from alphas and recoiling nuclei. An acrylic purification technique and two coating techniques are described: a solvent-borne (tested on DEAP-1) and solvent-less (being developed for the full scale DEAP-3600 detector).

  4. Influence of Irradiated Chitosan on Growth and Flower Quality of Gladiolus at Different Sowing Dates and Synthesis of Radiation Cross-Linked Poly(Acrylic Acid) Hydrogel for Agriculture Applications. Chapter 14

    The plant growth promoter activity of irradiated chitosan on Gladiolus hortulanus cv. Amsterdam was studied. Chitosan was applied in the form of foliar spray at third leaf stage. Corms were sown at three different dates with 15-day intervals. Data on several parameters such as survival percentage, leaf area, plant height, number of florets per spike, and vase life were collected. Chitosan-treated plants showed superior results as compared to the control samples. Acrylic acid-based superabsorbent hydrogel was prepared using phenyltriethoxysilane (PTES) as cross-linker. Different amounts of PTES were incorporated and irradiated at different doses of up to a maximum of 30 kGy. The cross-linked acrylic acid showed hydrogel properties, and its swelling kinetics, gel fraction, and equilibrium degree of swelling (EDS) were studied. The swelling of hydrogel was also affected by pH, ionic strength, and temperature. These hydrogels can be further explored as a super water absorbent material in semi-arid and drought prone areas. (author)

  5. Synthesis of linear low-density polyethylene-g-poly (acrylic acid)-co-starch/organo-montmorillonite hydrogel composite as an adsorbent for removal of Pb(Ⅱ) from aqueous solutions

    Maryam Irani; Hanafi Ismail; Zulkifli Ahmad; Maohong Fan

    2015-01-01

    The purpose of this work is to remove Pb(Ⅱ) from the aqueous solution using a type of hydrogel composite.A hydrogel composite consisting of waste linear low density polyethylene,acrylic acid,starch,and organo-montmorillonite was prepared through emulsion polymerization method.Fourier transform infrared spectroscopy (FTIR),Solid carbon nuclear magnetic resonance spectroscopy (CNMR)),silicon-29 nuclear magnetic resonance spectroscopy (Si NMR)),and X-ray diffraction spectroscope ((XRD) were applied to characterize the hydrogel composite.The hydrogel composite was then employed as an adsorbent for the removal of Pb(Ⅱ) from the aqueous solution.The Pb(Ⅱ)-loaded hydrogel composite was characterized using Fourier transform infrared spectroscopy (FTIR)),scanning electron microscopy (SEM)),and X-ray photoelectron spectroscopy ((XPS)).From XPS results,it was found that the carboxyl and hydroxyl groups of the hydrogel composite participated in the removal of Pb(Ⅱ).Kinetic studies indicated that the adsorption of Pb(Ⅱ)followed the pseudo-second-order equation.It was also found that the Langmuir model described the adsorption isotherm better than the Freundlich isotherm.The maximum removal capacity of the hydrogel composite for Pb(Ⅱ) ions was 430 mg/g.Thus,the waste linear low-density polyethylene-g-poly (acrylic acid)-co-starch/organo-montmorillonite hydrogel composite could be a promising Pb(Ⅱ) adsorbent.

  6. Hyperbranched urethane-acrylates

    Tasić Srba

    2004-01-01

    Full Text Available The synthesis, characterization and UV-curing of hyperbranched urethaneacrylates (HB-UA were investigated in this study. They were evaluated as oli-gomers in model UV curable coatings. HB-UAs were synthesized by reaction of an aliphatic hyperbranched polyester of the second generation (HBRG2 and an isocyanate adduct, obtained by the reaction of isophoronediisocyana-te and different hydroxy alkyl acrylates. Their thermal properties and viscosities depend on the degree of modification of HBRG2 and the type of hydroxy alkyl acrylate used. The introduction of a flexible alkoxylated spacer between the HBP core and acrylate end groups reduces steric hindrance by moving the cross linkable acrylate groups away from the HBP core and increase its reactivity. Due to the presence of abstractable H-atoms in the α-position to the ether links, HB-UAs based on poly(ethylene oxide monoacrylate are very reactive and do not show oxygen inhibition. The obtained coatings combine a high cross linking density with flexible segments between the cross links, which results in a good compromise between hardness and flexibility and have the potential to be used in different UV-curing applications.

  7. Conversion of Lignocellulosic Biomass to Ethanol and Butyl Acrylate

    Binder, Thomas [Archer Daniels Midland Company, Decatur, IL (United States); Erpelding, Michael [Archer Daniels Midland Company, Decatur, IL (United States); Schmid, Josef [Archer Daniels Midland Company, Decatur, IL (United States); Chin, Andrew [Archer Daniels Midland Company, Decatur, IL (United States); Sammons, Rhea [Archer Daniels Midland Company, Decatur, IL (United States); Rockafellow, Erin [Archer Daniels Midland Company, Decatur, IL (United States)

    2015-04-10

    Conversion of Lignocellulosic Biomass to Ethanol and Butyl Acrylate. The purpose of Archer Daniels Midlands Integrated Biorefinery (IBR) was to demonstrate a modified acetosolv process on corn stover. It would show the fractionation of crop residue to distinct fractions of cellulose, hemicellulose, and lignin. The cellulose and hemicellulose fractions would be further converted to ethanol as the primary product and a fraction of the sugars would be catalytically converted to acrylic acid, with butyl acrylate the final product. These primary steps have been demonstrated.

  8. Poly(ethylene-co-acrylic acid)-g-poly(ethylene glycol) graft copolymer templated synthesis of mesoporous TiO2 thin films for quasi-solid-state dye sensitized solar cells

    An amphiphilic graft copolymer, poly(ethylene-co-acrylic acid)-graft-poly(ethylene glycol) (PEAA-g-PEG), consisting of a PEAA backbone and PEG side chains was synthesized via an esterification reaction. 1H nuclear magnetic resonance and Fourier-transformed infrared analysis demonstrated esterification between carboxylic acid of PEAA and hydroxyl group of PEG. Small angle X-ray scattering results revealed that the crystalline domain spacing of PEAA increased from 11.3 to 12.8 nm upon using a more polar solvent with a higher affinity for poly(acrylic acid), while the crystalline domain spacing of PEAA disappeared with PEG grafting, indicating structural change to an amorphous state. Mesoporous TiO2 thin films were synthesized via a sol–gel reaction using PEAA-g-PEG graft copolymer as a structure-directing agent. The hydrophilically-preformed TiO2 nanoparticles were selectively confined in the hydrophilic PEG domains of the graft copolymer, and mesoporous TiO2 thin films were formed, as confirmed by scanning electron microscopy. The morphology of TiO2 films was tunable by varying the concentrations of polymer solutions and the amount of preformed TiO2. A quasi-solid-state dye-sensitized solar cell fabricated with PEAA-g-PEG templated TiO2 film exhibited an energy conversion efficiency of 3.8% at 100 mW/cm2, which was greater than that of commercially-available paste (2.6%) at a similar film thickness (3 μm). The improved performance was due to the larger surface area for high dye loading and organized structure with good interconnectivity. - Highlights: • Poly(ethylene-co-acrylic acid)-g-poly(ethylene glycol) (PEAA-g-PEG) graft copolymer is synthesized. • Amphiphilic PEAA-g-PEG acts as a structure directing agent. • Mesoporous TiO2 thin films are prepared by sol–gel reaction using PEAA-g-PEG template. • Efficiency of DSSC with templated TiO2 is greater than with commercial TiO2 paste

  9. Properties of Acrylic Acid Resin Coating Materials Modified by Carbon Nanotubes%碳纳米管改性丙烯酸树脂涂饰材料的性能研究

    孙友昌; 马建中; 鲍艳; 刘海腾; 于玉龙

    2011-01-01

    Firstly, carbon nanotubes were modified and purified by the mix acids, then surface properties of carbon nanotubes were analyzed with the help of the infrared detector. Vinyl leather finishing agent was modified by carbon nanotubes using physical blending and in - situ emulsion polymerization. Tensile strength, elongation at break and water resistance of acrylic resin mem- brane nano- composite coating agent were determined. The results show that carbon nanotubes has the obvious enhancement toughening effect to acrylic resin membrane. Acrylic resin modified by carbon nanotubes has better tensile strength and elongation at break with an increase in the amount of carbon nanotubes, but has worse water resistance. Acrylic resin membrane modified by carbon nanotubes using physical blending and in - situ emulsion polymerization, the comprehensive performance is the best when the dosage of CNTs respectively is 0.04% and 0. 03%. Ultrasonic treatment will decrease the tensile strength and elongation at break, but the water resistance of the film will be increased slightly.%采用混酸对碳纳米管(CNTs)进行改性和纯化,并以此为原料,分别采用物理共混与原位乳液聚合法制备碳纳米管改性丙烯酸树脂皮革涂饰剂,将制备的丙烯酸树脂乳液分别成膜,并对所成薄膜的抗张强度、断裂伸长率、耐水性等进行测定。结果表明:碳纳米管对丙烯酸树脂薄膜有明显的增强增韧效果,随着碳纳米管用量的增加,薄膜的抗张强度、断裂伸长率增加,但耐水性略有下降。采用物理共混法与原位乳液聚合法改性丙烯酸树脂乳液,当CNTs的用量分别为0.04%和0.03%时,改性丙烯酸树脂薄膜的综合性能最好。对改性后的乳液进行超声处理,可使

  10. Synthesis of highly carboxylate acrylic resins for leather impregnation

    Ollé Otero, Lluís; Solé, M.M.; Shendrik, Alexander; Labastida, L.; Bacardit Dalmases, Anna

    2012-01-01

    This work describes the synthesis of new leather finishing acrylic resins. Four resins ware synthesized varying the concentration of ethyl acrylate, and metracrylic acid. Sodium lauryl sulphate was used as emulsifying system. By means of an experimental design, an optimal resin for leather impregnation was defined. The results obtained indicated that the variation of the monomer concentration influences the resin properties, the hardness of the film, and the penetration into the leather. Most...

  11. Neutral, anionic, cationic, and zwitterionic diblock copolymers featuring poly(2-methoxyethyl acrylate) hydrophobic segments

    Javakhishvili, Irakli; Jankova Atanasova, Katja; Hvilsted, Søren

    2013-01-01

    Amphiphilic diblock copolymers incorporating hydrophobic poly(2-methoxyethyl acrylate) (PMEA) and hydrophilic neutral poly(ethylene glycol) monomethyl ether (mPEG), anionic poly(acrylic acid) (PAA) and poly(methacrylic acid) (PMAA), cationic poly(2-dimethylaminoethyl methacrylate) (PDMAEMA), and...

  12. Synthesis, Characterization, and Aqueous Lubricating Properties of Amphiphilic Graft Copolymers Comprising 2-Methoxyethyl Acrylate

    Javakhishvili, Irakli; Røn, Troels; Jankova Atanasova, Katja; Hvilsted, Søren; Lee, Seunghwan

    2014-01-01

    Amphiphilic anionic and cationic graft copolymers possessing poly(2-hydroxyethyl methacrylate) (PHEMA) backbone and poly(methacrylic acid), poly(2-methoxyethyl acrylate-co-methacrylic acid), and poly(2-methoxyethyl acrylate-co-2-(dimethylamino)ethyl methacrylate) grafts are constructed by merging...

  13. Effects of alumina air-abrasion and acidic priming agents on bonding between SUS XM27 steel and auto-polymerizing acrylic resin.

    Ishikawa, Yumi; Ohashi, Norihisa; Koizumi, Hiroyasu; Tanoue, Naomi; Nishiyama, Norihiro; Matsumura, Hideo

    2007-09-01

    The purpose of this study was to evaluate the effects of functional monomers contained in the primers, as well as alumina particle abrasion on bonding between stainless steel and acrylic resin. SUS XM27 steel was primed with one of the following materials; Alloy Primer, Estenia Opaque Primer, M. L. Primer, and Super-Bond Liquid. Steel disks were either ground flat or alumina-blasted, primed with one of the four agents, and bonded with an acrylic resin (Unifast Trad). Bond strength was determined both before and after thermocycling (2,000 or 20,000 cycles). Among the four priming agents, the Alloy Primer and Estenia Opaque Primer, both of which contain 10-methacryloyloxydecyl dihydrogen phosphate (MDP), exhibited better bonding performance than the others. Alumina air-borne particle abrasion considerably improved the durability of bonding between the steel and the resin material. It can be concluded that alumina blasting followed by priming with an MDP agent is recommended for bonding the resin and SUS XM27 steel. PMID:17928724

  14. Constrained photophysics of partially and fully encapsulated charge transfer probe (E)-3-(4-Methylaminophenyl) acrylic acid methyl ester inside cyclodextrin nano-cavities: Evidence of cyclodextrins cavity dependent complex stoichiometry

    Ghosh, Shalini; Jana, Sankar; Guchhait, Nikhil

    2011-12-01

    The polarity sensitive intra-molecular charge transfer (ICT) emission from (E)-3-(4-Methylaminophenyl) acrylic acid methyl ester (MAPAME) is found to show distinct changes once introduced into the nano-cavities of cyclodextrins in aqueous environment. Movement of the molecule from the more polar aqueous environment to the less polar, hydrophobic cyclodextrin interior is marked by the blue shift of the CT emission band with simultaneous fluorescence intensity enhancement. The emission spectral changes on complexation with the α- and β-CD show different stoichiometries as observed from the Benesi-Hildebrand plots. Fluorescence anisotropy and lifetime measurements were performed to probe the different behaviors of MAPAME in aqueous α- and β-CD solutions.

  15. 丙烯酸改性氯化聚丙烯的合成和粘接性能的研究%Study on synthesis and adhesiveness of modified chlorinated polypropylene with acrylic acid

    傅和青; 黄洪; 张心亚; 陈焕钦

    2004-01-01

    氯化聚丙烯是聚丙烯的氯化改性产物,通过改性,其硬度、耐磨性、耐酸性、耐盐水性能比聚丙烯都好,耐热、耐老化性也优于聚丙烯.但其性能尤其是粘接性能还不能满足其在胶粘剂等方面的需要,为了进一步提高氯化聚丙烯的粘接性能,拓宽其应用领城,需对氯化聚丙烯改性.接枝共聚法是一种很好的化学改性方法.本文以丙烯酸(AA)作为接枝单体,以过氧化苯甲酰(BPO)为引发剂,以甲苯为溶剂,采用液相接枝共聚法,将丙烯酸单体接枝到氯化聚丙烯大分子链上,得到丙烯酸改性氯化聚丙烯产物.系统研究了反应温度、反应时间、引发剂过氧化苯甲酰用量和丙烯酸单体用量等因素对丙烯酸接枝改性的氯化聚丙烯产物粘接性能的影响,得出了较佳的工艺条件是反应温度T=100℃,反应时间t=3.5 h,原料质量配比为100份氯化聚丙烯、3份丙烯酸和0.3份的过氧化二苯甲酰.研究还表明,丙烯酸改性的氯化聚丙烯的粘接性能优于氯化聚丙烯的粘接性能.%Grafting of acrylic acid (AA) on chlorinated polypropylene (CPP) by free radical process was carried out at different temperatures and hours using toluene as solvent. The effect of temperature,time,initiator concentration and the ratio of chlorinated polypropylene and acrylic acid on the adhesiveness was studied. The optimum processing conditions were that the reaction temperature was 100 ℃, reaction time was 3.5 h,based on 100 parts chlorinated polypropylene 3 parts of acrylic acid and 0.30 parts benzoyl peroxide (BPO) were used. The adhesiveness of modified chlorinated polypropylene with acrylic acid was better than that of chlorinated polypropylene.

  16. The influence of the partial pressure of air on the extent of surface and bulk grafting during the mutual irradiation of acrylic acid vapour and low-density polyethylene

    The influence of the partial pressure of air on the extent of grafting during the mutual irradiation (γ-ray) of acrylic acid vapour and low-density polyethylene films has been monitored by ESCA and infra-red spectroscopy. It was found that increasing the pressure at which the reaction tube was sealed from 8 x 10-5 to 2 x 10-4 Torr did not change the extent of bulk grafting but drastically reduced that on the surface, and gave rise to an embedded graft. The surface of the embedded graft is crosslinked. The degree of crosslinking also appears to be dependent on the partial pressure of air (i.e. oxygen). (author)

  17. Analysis and Testing of Bisphenol A—Free Bio-Based Tannin Epoxy-Acrylic Adhesives

    Shayesteh Jahanshahi

    2016-04-01

    Full Text Available A tannin-based epoxy acrylate resin was prepared from glycidyl ether tannin (GET and acrylic acid. The influence of the reaction condition for producing tannin epoxy acrylate was studied by FT-MIR, 13C-NMR, MALDI-TOF spectroscopy and shear strength. The best reaction conditions for producing tannin epoxy acrylate resin without bisphenol A was by reaction between GET and acrylic acid in the presence of a catalyst and hydroquinone at 95 °C for 12 h. FT-MIR, 13C-NMR and MALDI-TOF analysis have confirmed that the resin has been prepared under these conditions. The joints bonded with this resin were tested for block shear strength. The results obtained indicated that the best strength performance was obtained by the bioepoxy-acrylate adhesive resin prepared at 95 °C for a 12-h reaction.

  18. ITX/EDAB光引发丙烯酸溶液聚合动力学%Kinetic study on the photoinitiated polymerization of acrylic acid initiated using isopropylthioxanthone/ethyl-4(dimethylamino)benzoate pair

    李会玲; 杨万泰

    2001-01-01

    以异丙基硫杂蒽酮(ITX)/对-(二甲基氨基)苯甲酸乙酯(EDAB)为复配引发剂,研究了光引发丙烯酸溶液聚合动力学。结果表明,RP与单体浓度呈一次关系,引发剂反应级数在低浓度(<0.2 mmol/L)下为0.205 7,高浓度(>0.8 mmol/L)下为-0.1;反应速率存在最大值,此时引发剂浓度为0.8 mmol/L;聚合反应表观活化能为9.53 kJ/mol。%A kinetic study on the photo-induced polymerization of acrylic acid with ITX/EDAB as photo-initiator was carried out. The propagation reaction rate of acrylic acid was linear with monomer concentration. It was also found that the order of photo-initiator changed from 0.205 7 at low concentration(<0.2 mmol/L) to -0.1 at high concentration(>0.8 mmol/L). The maximum rate was obtained when the concentration of the initiator was 0.8 mmol/L. The apparant activation energy of polymerization was 9.53 kJ/mol.

  19. [Treatment of acrylate wastewater by electrocatalytic reduction process].

    Yu, Li-Na; Song, Yu-Dong; Zhou, Yue-Xi; Zhu, Shu-Quan; Zheng, Sheng-Zhi; Ll, Si-Min

    2011-10-01

    High-concentration acrylate wastewater was treated by an electrocatalytic reduction process. The effects of the cation exchange membrane (CEM) and cathode materials on acrylate reduction were investigated. It indicated that the acrylate could be reduced to propionate acid efficiently by the electrocatalytic reduction process. The addition of CEM to separator with the cathode and anode could significantly improve current efficiency. The cathode materials had significant effect on the reduction of acrylate. The current efficiency by Pd/Nickel foam, was greater than 90%, while those by nickel foam, the carbon fibers and the stainless steel decreased successively. Toxicity of the wastewater decreased considerably and methane production rate in the biochemical methane potential (BMP) test increased greatly after the electrocatalytic reduction process. PMID:22279908

  20. [Acrylic resin removable partial dentures

    Baat, C. de; Witter, D.J.; Creugers, N.H.J.

    2011-01-01

    An acrylic resin removable partial denture is distinguished from other types of removable partial dentures by an all-acrylic resin base which is, in principle, solely supported by the edentulous regions of the tooth arch and in the maxilla also by the hard palate. When compared to the other types of

  1. Adsorption mechanism and dispersion efficiency of three anionic additives [poly(acrylic acid), poly(styrene sulfonate) and HEDP] on zinc oxide.

    Dange, C; Phan, T N T; André, V; Rieger, J; Persello, J; Foissy, A

    2007-11-01

    Adsorption on ZnO of sodium poly(acrylate) (PAA), sodium poly(styrene sulfonate) (PSS) and a monomer surfactant [hydroxyethylidene diphosphonate (HEDP)] was investigated in suspensions initially equilibrated at pH 7. Results demonstrate interplay in the adsorption mechanism between zinc complexation, salt precipitation, and ZnO dissolution. In the case of PAA, the adsorption isotherm exhibits a maximum attributed to the precipitation of zinc polyacrylate. PSS and HEDP formed high-affinity adsorption isotherms, but the plateau adsorption of HEDP was significantly lower than that of PSS. The adsorption isotherm of each additive is divided into two areas. At low additive concentration (high zinc/additive ratio), the total zinc concentration in the solution decreased and the pH increased upon addition. At a higher additive ratio, zinc concentration and pH increased with the organic concentration. The increase in pH is due to the displacement of hydroxyl ions from the surface and the increase in zinc concentration results from the dissolution of ZnO due to the complexation of zinc ions by the organics. The stability of the ZnO dispersions was investigated by measurement of the particle size distribution after addition of various amounts of polymers. The three additives stabilized the ZnO dispersions efficiently once full surface coverage was reached. PMID:17720181

  2. Epoxy-acrylic core-shell particles by seeded emulsion polymerization.

    Chen, Liang; Hong, Liang; Lin, Jui-Ching; Meyers, Greg; Harris, Joseph; Radler, Michael

    2016-07-01

    We developed a novel method for synthesizing epoxy-acrylic hybrid latexes. We first prepared an aqueous dispersion of high molecular weight solid epoxy prepolymers using a mechanical dispersion process at elevated temperatures, and we subsequently used the epoxy dispersion as a seed in the emulsion polymerization of acrylic monomers comprising methyl methacrylate (MMA) and methacrylic acid (MAA). Advanced analytical techniques, such as scanning transmission X-ray microscopy (STXM) and peak force tapping atomic force microscopy (PFT-AFM), have elucidated a unique core-shell morphology of the epoxy-acrylic hybrid particles. Moreover, the formation of the core-shell morphology in the seeded emulsion polymerization process is primarily attributed to kinetic trapping of the acrylic phase at the exterior of the epoxy particles. By this new method, we are able to design the epoxy and acrylic polymers in two separate steps, and we can potentially synthesize epoxy-acrylic hybrid latexes with a broad range of compositions. PMID:27078740

  3. Preparation and properties of UV curable acrylic PSA by vinyl bonded graphene oxide

    Pang, Beili; Ryu, Chong-Min; Jin, Xin; Kim, Hyung-Il

    2013-11-01

    Acrylic pressure sensitive adhesives (PSAs) with higher thermal stability for thin wafer handling were successfully prepared by forming composite with the graphene oxide (GO) nanoparticles modified to have vinyl groups via subsequent reaction with isophorone diisocyanate and 2-hydroxyethyl methacrylate. The acrylic copolymer was synthesized as a base resin for PSAs by solution radical polymerization of ethyl acrylate, 2-ethylhexyl acrylate, and acrylic acid followed by further modification with GMA to have the vinyl groups available for UV curing. The peel strength of PSA decreased with the increase of gel content which was dependent on both modified GO content and UV dose. Thermal stability of UV-cured PSA was improved noticeably with increasing the modified GO content mainly due to the strong and extensive interfacial bonding formed between the acrylic copolymer matrix and GO fillers

  4. Advances in acrylic-alkyd hybrid synthesis and characterization

    Dziczkowski, Jamie

    2008-10-01

    In situ graft acrylic-alkyd hybrid resins were formed by polymerizing acrylic and acrylic-mixed monomers in the presence of alkyds by introduction of a free radical initiator to promote graft formation. Two-dimensional NMR, specifically gradient heteronuclear multiple quantum coherence (gHMQC), was used to clarify specific graft sites of the hybrid materials. Both individual and mixed-monomer systems were produced to determine any individual monomer preferences and to model current acrylic-alkyd systems. Different classes of initiators were used to determine any initiator effects on graft location. The 2D-NMR results confirm grafting at doubly allylic hydrogens located on the fatty acid chains and the polyol segment of the alkyd backbone. The gHMQC spectra show no evidence of grafting across double bonds on either pendant fatty acid groups or THPA unsaturation sites for any of the monomer or mixed monomer systems. It was also determined that choice of initiator has no effect on graft location. In addition, a design of experiments using response surface methodology was utilized to obtain a better understanding of this commercially available class of materials and relate both the chemical and physical properties to one another. A Box-Behnkin design was used, varying the oil length of the alkyd phase, the degree of unsaturation in the polyester backbone, and acrylic to alkyd ratio. Acrylic-alkyd hybrid resins were reduced with an amine/water mixture. Hydrolytic stability was tested and viscoelastic properties were obtained to determine crosslink density. Cured films were prepared and basic coatings properties were evaluated. It was found that the oil length of the alkyd is the most dominant factor for final coatings properties of the resins. Acrylic to alkyd ratio mainly influences the resin properties such as acid number, average molecular weight, and hydrolytic stability. The degree of unsaturation in the alkyd backbone has minimal effects on resin and film

  5. The use of epoxidised palm oil products (EPOP) for the synthesis of radiation curable resins 1. Synthesis of epoxidised RBD palm olein acrylate

    The synthesis of acrylated olein utilizing epoxidised refined, bleached and deodorized (RBD) palm olein has been carried out by acrylation reaction. This is done by the introduction of acrylic acid into oxirane group of the epoxidised RBD palm olein. The reaction was confirmed by analytical data i.e. oxirane oxygen content, iodine value and acid value and IR spectrophotometric method. It was found that, oxirane group in triglyceride molecule of epoxidised RBD palm olein (EPOL) is attacked by acrylic acid to yield epoxidised RBD palm olein acrylate (EPOLA). The EPOLA was found curable when subjected to ultraviolet radiation

  6. Synthesis of Radiation Curable Palm Oil–Based Epoxy Acrylate: NMR and FTIR Spectroscopic Investigations

    Ashraf M. Salih

    2015-08-01

    Full Text Available Over the past few decades, there has been an increasing demand for bio-based polymers and resins in industrial applications, due to their potential lower cost and environmental impact compared with petroleum-based counterparts. The present research concerns the synthesis of epoxidized palm oil acrylate (EPOLA from an epoxidized palm oil product (EPOP as environmentally friendly material. EPOP was acrylated by acrylic acid via a ring opening reaction. The kinetics of the acrylation reaction were monitored throughout the reaction course and the acid value of the reaction mixture reached 10 mg KOH/g after 16 h, indicating the consumption of the acrylic acid. The obtained epoxy acrylate was investigated intensively by means of FTIR and NMR spectroscopy, and the results revealed that the ring opening reaction was completed successfully with an acrylation yield about 82%. The UV free radical polymerization of EPOLA was carried out using two types of photoinitiators. The radiation curing behavior was determined by following the conversion of the acrylate groups. The cross-linking density and the hardness of the cured EPOLA films were measured to evaluate the effect of the photoinitiator on the solid film characteristics, besides, the thermal and mechanical properties were also evaluated.

  7. 壳聚糖钯配合物磁微球的合成及其在催化丙烯酸与碘代苯反应中的性能%Synthesis of a magnetic-separated chitosan-palladium complex and its catalytic activity in the reaction of acrylic acid with iodobenzene

    杨黎明; 张群飞; 陈捷; 曹芳琦; 戎亮; 曹春燕

    2008-01-01

    A magnetic-separated catalyst of chitosan-palladium complex (Fe3O4-CS-Pd) based on chitosan coated Fe3O4 microspheres was prepared by the "bottom-up" approach. The catalytic behavior of the catalyst in the cross coupling reaction of acrylic acid (AA) with iodobenzene (ArI) was investigated. Compared with the traditional homogeneous palladium catalysts, the catalyst was easily separated and reused.

  8. Selective surface functionalization of polystyrene induced by synchrotron or UV radiation in the presence of oxygen or acrylic acid vapors; Funcionalizacao superficial seletiva de poliestireno induzida por radiacao sincrotron ou ultravioleta

    Kessler, Felipe; Kuhn, Sidiney; Weibel, Daniel E., E-mail: felipekessler@gmail.co [Universidade Federal do Rio Grande do Sul (IQ/UFRGS), Porto Alegre, RS (Brazil) Inst. de Quimica. Dept. de Fisico-Quimica

    2009-07-01

    Efficient surface functionalization of Polystyrene (PS) thin films by electromagnetic radiation in combination with a reactive gaseous atmosphere was obtained. Monochromatic synchrotron (SR) or polychromatic UV radiation were used as excitation sources. When SR was used, O{sub 2} was introduced after irradiation into the UHV chamber. UV irradiation was carried out keeping a constant flow of O{sub 2} or acrylic acid (AA) vapors during the photolysis. FTIR-ATR and XPS-NEXAFS spectra were obtained at the UFRGS and the LNLS, Campinas respectively. PS films were functionalized by monochromatic SR and then expose to O{sub 2} at specific transitions such us C 1s {yields}{sigma}{sup *}{sub C-C} excitation. It was found a high rate of COO, C=O and C-O groups at the surface (> 70%). UV-assisted treatment in the presence of AA vapors showed that an efficient polymerization process took place, such as, it was observed in previous AA low pressure RF plasma treatments. UV-assisted functionalization has the advantage of lower costs and simple set-up compared to plasma treatments. (author)

  9. Investigation of Changes in the Microscopic Structure of Anionic Poly(N-isopropylacrylamide-co-Acrylic acid) Microgels in the Presence of Cationic Organic Dyes toward Precisely Controlled Uptake/Release of Low-Molecular-Weight Chemical Compound.

    Kureha, Takuma; Shibamoto, Takahisa; Matsui, Shusuke; Sato, Takaaki; Suzuki, Daisuke

    2016-05-10

    Changes in a microscopic structure of an anionic poly(N-isopropylacrylamide-co-acrylic acid) microgel were investigated using small- and wide-angle X-ray scattering (SWAXS). The scattering profiles of the microgels were analyzed in a wide scattering vector (q) range of 0.07 ≤ q/nm(-1) ≤ 20. In particular, the microscopic structure of the microgel in the presence of a cationic dye rhodamine 6G (R6G) was characterized in terms of its correlation length (ξ), which represents the length scale of the spatial correlation of the network density fluctuations, and characteristic distance (d*), which originated from the local packing of isopropyl groups of two neighboring chains. In the presence of cationic R6G, ξ exhibited a divergent-like behavior, which was not seen in the absence of R6G, and d* was decreased with decreasing the volume of the microgel upon increasing temperature. At the same time, the amount of R6G adsorbed per unit mass of the microgel increased upon heating. These results suggested that a coil-to-globule transition of the poly(N-isopropylacrylamide) chains in the present anionic microgel occurred because of efficiently screened, thus, short ranged electrostatic repulsion between the charged groups, and hydrophobic interaction between the isopropyl groups in the presence of cationic R6G. The combination of hydrophobic and electrostatic interaction between the cationic dye and the microgel affected the separation and volume transition behavior of the microgel. PMID:27101468

  10. Cyto- and genotoxicological assessment and functional characterization of N-vinyl-2-pyrrolidone-acrylic acid-based copolymeric hydrogels with potential for future use in wound healing applications

    Kirf, Dominik; Devery, Sinead M [Department of Life and Physical Science, Athlone Institute of Technology (Ireland); Higginbotham, Clement L [Materials Research Institute, Athlone Institute of Technology (Ireland); Rowan, Neil J, E-mail: sdevery@ait.i, E-mail: dkirf@ait.i, E-mail: chigginbotham@ait.i, E-mail: nrowan@ait.i [Department of Nursing and Health Science, Athlone Institute of Technology (Ireland)

    2010-06-01

    This study investigated the toxicity of N-vinyl-2-pyrrolidone-acrylic acid copolymer hydrogels crosslinked with ethylene glycol dimethacrylate or poly(ethylene glycol) dimethacrylate. There is a pressing need to establish the toxicity status of these new copolymers because they may find applications in future wound healing processes. Investigations revealed that the capacity of these hydrogels for swelling permitted the retention of high amounts of water yet still maintaining structural integrity. Reverse phase HPLC analysis suggested that unreacted monomeric base material was efficiently removed post-polymerization by applying an additional purification process. Subsequently, in vitro toxicity testing was performed utilizing direct and indirect contact exposure of the polymers to human keratinocytes (HaCaT) and human hepatoma (HepG2) cells. No indication of significant cell death was observed using the established MTT, neutral red (NR) and fluorescence-based toxicity endpoint indicators. In addition, the alkaline Comet assay showed no genotoxic effects following cell exposure to hydrogel extracts. Investigations at the nucleotide level using the Ames mutagenicity assay demonstrated no evidence of mutagenic activity associated with the polymers. Findings from this study demonstrated that these hydrogels are non-cytotoxic and further work can be carried out to investigate their potential as a wound-healing device that will impact positively on patient health and well-being.

  11. Cyto- and genotoxicological assessment and functional characterization of N-vinyl-2-pyrrolidone-acrylic acid-based copolymeric hydrogels with potential for future use in wound healing applications

    This study investigated the toxicity of N-vinyl-2-pyrrolidone-acrylic acid copolymer hydrogels crosslinked with ethylene glycol dimethacrylate or poly(ethylene glycol) dimethacrylate. There is a pressing need to establish the toxicity status of these new copolymers because they may find applications in future wound healing processes. Investigations revealed that the capacity of these hydrogels for swelling permitted the retention of high amounts of water yet still maintaining structural integrity. Reverse phase HPLC analysis suggested that unreacted monomeric base material was efficiently removed post-polymerization by applying an additional purification process. Subsequently, in vitro toxicity testing was performed utilizing direct and indirect contact exposure of the polymers to human keratinocytes (HaCaT) and human hepatoma (HepG2) cells. No indication of significant cell death was observed using the established MTT, neutral red (NR) and fluorescence-based toxicity endpoint indicators. In addition, the alkaline Comet assay showed no genotoxic effects following cell exposure to hydrogel extracts. Investigations at the nucleotide level using the Ames mutagenicity assay demonstrated no evidence of mutagenic activity associated with the polymers. Findings from this study demonstrated that these hydrogels are non-cytotoxic and further work can be carried out to investigate their potential as a wound-healing device that will impact positively on patient health and well-being.

  12. Preparation of Uniform-Sized and Dual Stimuli-Responsive Microspheres of Poly(N-Isopropylacrylamide/Poly(Acrylic acid with Semi-IPN Structure by One-Step Method

    En-Ping Lai

    2016-03-01

    Full Text Available A novel strategy was developed to synthesize uniform semi-interpenetrating polymer network (semi-IPN microspheres by premix membrane emulsification combined with one-step polymerization. Synthesized poly(acrylic acid (PAAc polymer chains were added prior to the inner water phase, which contained N-isopropylacrylamide (NIPAM monomer, N,N′-methylene bisacrylamide (MBA cross-linker, and ammonium persulfate (APS initiator. The mixtures were pressed through a microporous membrane to form a uniform water-in-oil emulsion. By crosslinking the NIPAM in a PAAc-containing solution, microspheres with temperature- and pH-responsive properties were fabricated. The semi-IPN structure and morphology of the microspheres were confirmed by Fourier transform infrared spectroscopy (FTIR, scanning electron microscopy (SEM, and transmission electron microscopy (TEM. The average diameter of the obtained microspheres was approximately 6.5 μm, with Span values of less than 1. Stimuli-responsive behaviors of the microspheres were studied by the cloud-point method. The results demonstrated that semi-IPN microspheres could respond independently to both pH and temperature changes. After storing in a PBS solution (pH 7.0 at 4 °C for 6 months, the semi-IPN microspheres remained stable without a change in morphology or particle size. This study demonstrated a promising method for controlling the synthesis of semi-IPN structure microspheres with a uniform size and multiple functionalities.

  13. Improvement in the Water Retention Characteristics of Sandy Loam Soil Using a Newly Synthesized Poly(acrylamide-co-acrylic Acid/AlZnFe2O4 Superabsorbent Hydrogel Nanocomposite Material

    Shaukat Ali Shahid

    2012-08-01

    Full Text Available The use of some novel and efficient crop nutrient-based superabsorbent hydrogel nanocomposites (SHNCs, is currently becoming increasingly important to improve the crop yield and productivity, due to their water retention properties. In the present study a poly(Acrylamide-co-acrylic acid/AlZnFe2O4 superabsorbent hydrogel nanocomposite was synthesized and its physical properties characterized using Energy Dispersive X-ray (EDX, FE-SEM and FTIR spectroscopic techniques. The effects of different levels of SHNC were studied to evaluate the moisture retention properties of sandy loam soil (sand 59%, silt 21%, clay 19%, pH 7.4, EC 1.92 dS/m. The soil amendment with 0.1, 0.2, 0.3 and 0.4 w/w% of SHNC enhanced the moisture retention significantly at field capacity compared to the untreated soil. Besides, in a separate experiment, seed germination and seedling growth of wheat was found to be notably improved with the application of SHNC. A delay in wilting of seedlings by 5–8 days was observed for SHNC-amended soil, thereby improving wheat plant growth and establishment.

  14. SYNTHESIS OF ACRYLIC ESTERS IN PTC: KINETICS AND ECOLOGICAL ASPECTS

    G.Torosyan

    2013-06-01

    Full Text Available The synthesis of esters of acrylic acids, which are applied for synthesis of polymeric materials by phase transfer catalysis were discussed (PTC, which is very useful for reduction of reaction consumption of materials and power.This method has substantial advantages including high speed of the process, soft condition of reaction and reduced pollution.

  15. (Liquid + liquid) equilibria in {l_brace}water + acrylic acid + (1-butanol, or 2-butanol, or 1-pentanol){r_brace} systems at T = 293.2 K, T = 303.2 K, and T = 313.2 K and atmospheric pressure

    Batistell, Melissa C.; Alves, Thiago C.; Guadagnini, Talita R.; Hadlich de Oliveira, Leonardo [School of Chemical Engineering, University of Campinas, Av. Albert Einstein 500, 13083-852 Campinas-SP (Brazil); Aznar, Martin, E-mail: maznar@feq.unicamp.br [School of Chemical Engineering, University of Campinas, Av. Albert Einstein 500, 13083-852 Campinas-SP (Brazil)

    2011-09-15

    Highlights: > Acrylic acid solubilizes preferably in the studied solvents than in water. > Immiscibility region increases in the order: 2-butanol < 1-butanol < 1-pentanol. > Immiscibility region reduces little with an increase in temperature. > K and S values show that 1-pentanol is the best studied solvent. - Abstract: (Liquid + liquid) equilibrium (LLE) data for {l_brace}water + acrylic acid + (1-butanol, or 2-butanol, or 1-pentanol){r_brace} at T = 293.2 K, T = 303.2 K, and T = 313.2 K and atmospheric pressure ({approx}95 kPa) were determined by Karl Fischer titration and densimetry. All systems present type I binodal curves. The size of immiscibility region changes little with an increase in temperature, but increases according to the solvent, following the order: 2-butanol < 1-butanol < 1-pentanol. Values of solute distribution and solvent selectivities show that 1-pentanol is a better solvent than 1-butanol or 2-butanol for acrylic acid removal from water solutions. Quality of data was ascertain by Hand and Othmer-Tobias equations, giving R{sup 2} > 0.916, mass balance and accordance between tie lines and cloud points. The NRTL model was used to correlate experimental data, by estimating new energy parameters, with root mean square deviations below 0.0053 for all systems.

  16. SORPTION OF Cu(II) BY POLY(HYDROXAMIC ACID) CHELATING EXCHANGER PREPARED FROM POL(YMETHYL ACRYLATE) GRAFTED OIL PALM EMPTY FRUIT BUNCH (OPEFB)

    Md Jelas Haron; Mariati Tiansih; Nor Azowa Ibrahim; Anuar Kassim; W. M. Z. Wan Yunus

    2009-01-01

    This paper describes the preparation of chemically modified oil palm empty fruit bunch (OPEFB) with hydroxamic acid functional group and its use for the sorption of Cu(II) from aqueous solution. OPEFB was grafted with poly(methylacrylate) (PMA), using H2O2/Fe2+ as initiator. The PMA grafted OPEFB (PMA-OPEFB) was treated with hydroxylammonium chloride in alkaline medium to produce hydroxamic acid grafted fiber (PHA-OPEFB). The FTIR spectrum of OPEFB grafted with PMA showed an intense absorpt...

  17. Synthesis and Demulsibility of the Terpolymer Demulsifier of Acryl Resin

    KANG,Wan-Li; MENG,Ling-Wei; ZHANG,Hong-Yan; LIU,Shu-Ren

    2008-01-01

    Terpolymer demulsifier of acryl resin has been synthesized through solution polymerization with water as a dissolvent,potassium persulfate as an initiator and the monomers of methyl methacrylate,butyl acrylate and acrylic acid as starting materials.The effects of the reaction temperature,dripping time,the amount of monomers and initiator on the dehydration rate of the demulsifier were investigated by an orthogonal experiment.It shows that the stronger influence on the dehydration rate among six factors is reaction temperature,dripping time,and amount of catalyst,while monomer has weak influence.The performance of the demulsifier was evaluated under different demulsification time,temperatures and concentrations of the screened demulsifiers.The result shows that the dehydration rate of the demulsifier can reach over 67%,which is better than that by the emulsion polymerization way.

  18. Biocatalytic functionalization of hydroxyalkyl acrylates and phenoxyethanol via phosphorylation.

    Tasnádi, Gábor; Hall, Mélanie; Baldenius, Kai; Ditrich, Klaus; Faber, Kurt

    2016-09-10

    The enzymatic phosphorylation of phenoxyethanol, 2-hydroxyethyl acrylate and 4-hydroxybutyl acrylate catalyzed by acid phosphatases PhoN-Sf and PiACP at the expense of inorganic di-, tri-, hexameta- or polyphosphate was applied to the preparative-scale synthesis of phosphorylated compounds. The reaction conditions were optimized with respect to enzyme immobilization, substrate concentration, pH and type of phosphate donor. The mild reaction conditions prevented undesired polymerization and hydrolysis of the acrylate ester moiety. Application of a continuous flow system allowed facile scale-up and mono-phosphates were obtained in up to 26% isolated yield with space-time yields of 0.89kgL(-1)h(-1). PMID:27422352

  19. Using NMR chemical shift imaging to monitor swelling and molecular transport in drug-loaded tablets of hydrophobically modified poly(acrylic acid): methodology and effects of polymer (in)solubility.

    Knöös, Patrik; Topgaard, Daniel; Wahlgren, Marie; Ulvenlund, Stefan; Piculell, Lennart

    2013-11-12

    A new technique has been developed using NMR chemical shift imaging (CSI) to monitor water penetration and molecular transport in initially dry polymer tablets that also contain small low-molecular weight compounds to be released from the tablets. Concentration profiles of components contained in the swelling tablets could be extracted via the intensities and chemical shift changes of peaks corresponding to protons of the components. The studied tablets contained hydrophobically modified poly(acrylic acid) (HMPAA) as the polymer component and griseofulvin and ethanol as hydrophobic and hydrophilic, respectively, low-molecular weight model compounds. The water solubility of HMPAA could be altered by titration with NaOH. In the pure acid form, HMPAA tablets only underwent a finite swelling until the maximum water content of the polymer-rich phase, as confirmed by independent phase studies, had been reached. By contrast, after partial neutralization with NaOH, the polyacid became fully miscible with water. The solubility of the polymer affected the water penetration, the polymer release, and the releases of both ethanol and griseofulvin. The detailed NMR CSI concentration profiles obtained highlighted the clear differences in the disintegration/dissolution/release behavior for the two types of tablet and provided insights into their molecular origin. The study illustrates the potential of the NMR CSI technique to give information of importance for the development of pharmaceutical tablets and, more broadly, for the general understanding of any operation that involves the immersion and ultimate disintegration of a dry polymer matrix in a solvent. PMID:24106807

  20. Mutagenicity assessment of acrylate and methacrylate compounds and implications for regulatory toxicology requirements.

    Johannsen, F R; Vogt, Barbara; Waite, Maureen; Deskin, Randy

    2008-04-01

    Esters of acrylic acid and methacrylic acid, more commonly known as acrylates and methacrylates, respectively, are key raw materials in the coatings and printing industry, with several of its chemical class used in food packaging. The results of over 200 short-term in vitro and in vivo mutagenicity studies available in the open literature have been evaluated. Despite differences in acrylate or methacrylate functionality or in the number of functional groups, a consistent pattern of test response was seen in a typical regulatory battery of mutagenicity tests. No evidence of point mutations was observed when acrylic acid or over 60 acrylates and methacrylates were investigated in Salmonella bacterial tests or in hprt mutation tests mammalian cells, and no evidence of a mutagenic effect was seen when tested in whole animal clastogenicity and/or aneuploidy (chromosomal aberration/micronucleus) studies. Consistent with the in vivo testing results, acrylic acid exhibited no evidence of carcinogenicity in chronic rodent cancer bioassays. In contrast, acrylic acid and the entire acrylate and methacrylate chemical class produced a consistently positive response when tested in the mouse lymphoma assay and/or other in vitro mammalian cell assays designed to detect clastogenicity. The biological relevance of this in vitro response is questioned based on the non-concordance of in vitro results with those of in vivo studies addressing the same mutagenic endpoint (clastogenicity). Thus, in short-term mutagenicity tests, the acrylates and methacrylates behave as a single chemical category, and genotoxicity behavior of a similar chemical can be predicted with confidence by inclusion within this chemical class, thus avoiding unnecessary testing. PMID:18346829

  1. Bonding auto-polymerising acrylic resin to acrylic denture teeth.

    Nagle, Susan

    2009-09-01

    This study investigated the effect of surface treatments on the shear bond strength of an auto-polymerising acrylic resin cured to acrylic denture teeth. The surface treatments included a combination of grit-blasting and\\/or wetting the surface with monomer. Samples were prepared and then stored in water prior to shear testing. The results indicated that the application of monomer to the surface prior to bonding did not influence the bond strength. Grit blasting was found to significantly increase the bond strength.

  2. SORPTION OF Cu(II BY POLY(HYDROXAMIC ACID CHELATING EXCHANGER PREPARED FROM POL(YMETHYL ACRYLATE GRAFTED OIL PALM EMPTY FRUIT BUNCH (OPEFB

    Md Jelas Haron

    2009-11-01

    Full Text Available This paper describes the preparation of chemically modified oil palm empty fruit bunch (OPEFB with hydroxamic acid functional group and its use for the sorption of Cu(II from aqueous solution. OPEFB was grafted with poly(methylacrylate (PMA, using H2O2/Fe2+ as initiator. The PMA grafted OPEFB (PMA-OPEFB was treated with hydroxylammonium chloride in alkaline medium to produce hydroxamic acid grafted fiber (PHA-OPEFB. The FTIR spectrum of OPEFB grafted with PMA showed an intense absorption band at 1734 cm-1 which is attributed to C=O vibration in the grafted ester. After hydroxylamine treatment, the intensity of absorption band at 1734 cm-1 decreased and new bands appeared at the 1640 cm-1 related to C=O vibration in hydroxamic acid and at the 1568 cm-1 related to the N-H amide. Sorption of Cu(II by PHA-OPEFB was effective over a pH range of 4 to 6. The sorption followed the Langmuir model with maximum capacities of 74.1 mg g-1 at 25 °C. The sorption process was exothermic, as shown by the negative value of enthalpy change, H. The free energy change (G for the sorption was negative, showing that the sorption process was spontaneous. A kinetic study showed that the Cu(II sorption followed a second order kinetic model.

  3. 粉体辐射接枝丙烯酸的聚偏氟乙烯超滤膜的制备%Preparation of PVDF-graft-poly(acrylic acid) UF Membranes

    卞晓锴; 施柳青; 于洋; 邓波; 李景烨; 陆晓峰

    2012-01-01

    PVDF-graft-poly (acrylic acid) (PVDF-g-PAA) was used as the material to prepare UF membrane via the phase inversion method. The solubility parameter of PVDF-g-PAA was tested. The effects of the type of solvents, polymer concentration, additives concentration, as well as the temperature of coagulation bath on the performance and structure of the PVDF-g-PAA membranes were discussed. The results showed that after being grafted with acrylic acid, the solubility parameter of PVDF-g-PAA was increased and the polarity of this polymer was enhanced. When DMF or NMP was used as solvent in the preparation of UF membranes, the membrane had a denser skin layer, a lower water flux and a higher rejection of BSA; when DMSO was used as solvent, there were some larger pores distributed on the membrane surface layer, and the membrane had the highest water flux and the lowest rejection of BSA; with the increase in the polymer concentration, the membrane structure became denser, the water flux decreased and the rejection of BSA increased; the increase in PEG400 concentration would lead to an increase in membrane flux and a more porous surface layer. Moreover, the thickness of the membranes also increased, and the starting position of macrovoids shifted further into the membranes; within the temperature range of 12-23 ℃ , with the increase in temperature, the flux of the membrane increased, and the rejection of BSA decreased.%采用粉体辐射接枝丙烯酸的聚偏氟乙烯( PVDF-g - PAA)为材料,以浸没沉淀相转化法制备PVDF- g- PAA超滤膜,研究了接枝后材料溶解性能的变化、以及溶剂种类、聚合物浓度、添加剂种类及浓度、凝胶浴温度制膜参数对PVDF- g- PAA膜结构及性能的影响.结果表明:辐射接枝丙烯酸后,聚合物的溶度参数增大,同时聚合物的极性也增强.在溶剂影响的考察中,以二甲基甲酰胺(DMF)和N-甲基吡咯烷酮(NMP)为溶剂制备的PVDF-g-PAA膜表面致密,透

  4. The use of superporous p(AAc (acrylic acid)) cryogels as support for Co and Ni nanoparticle preparation and as reactor in H2 production from sodium borohydride hydrolysis

    Here, we report for the first time the use of p(AAc (p(acrylic acid)) cryogel for in situ metal nanoparticle preparation, and their use as a superporous reactor for H2 generation from hydrolysis of NaBH4. Superporous p(AAc) cryogels and conventional hydrogels were prepared via free radical polymerization technique at low (−18 °C) and moderate (40 °C) temperatures, respectively. They were characterized by employing various methods such as swelling experiments, optical imaging, and SEM (Scanning Electron Microscopy) analysis. By reducing Co2+ and Ni2+ ions within p(AAc) cryogel and hydrogel matrices, the obtained Co and Ni metal nanoparticles were employed for H2 generation from NaBH4 hydrolysis. Various factors such as porosity, metal type, temperature, and the amount of sodium hydroxide were investigated to determine their effects on hydrogen generation from NaBH4 hydrolysis. Activation energy (Ea), enthalpy (ΔH#) and entropy (ΔS#) for NaBH4 hydrolysis by superporous p(AAc)-Co metal composites were 29.35 kJ mol−1,=36.85 kJ mol−1, and –157.88 J mol−1K−1, respectively. Cryogels showed better catalytic activity than conventional hydrogels in the hydrolysis reaction, and have a higher TOF (turnover frequency) value of 4.10 mol H2 (mol catalyst min)−1 compared to conventional hydrogels, due to its highly porous nature, short diffusion distances and fast response times. - Highlights: • Superporous cryogel supports for in situ metal nanoparticle preparation. • Fast H2 production from chemical hydride hydrolysis by cryogel-M composites. • Soft, superporous cryogel reactors for energy applications

  5. Evaluation of the antifouling and photocatalytic properties of poly(vinylidene fluoride) plasma-grafted poly(acrylic acid) membrane with self-assembled TiO{sub 2}

    You, Sheng-Jie, E-mail: sjyou@cycu.edu.tw [Department of Bioenvironmental Engineering, Chung Yuan Christian University, Chungli, Taiwan (China); R and D Center for Membrane Technology, Chung Yuan Christian University, Chungli, Taiwan (China); Semblante, Galilee Uy [Department of Bioenvironmental Engineering, Chung Yuan Christian University, Chungli, Taiwan (China); R and D Center for Membrane Technology, Chung Yuan Christian University, Chungli, Taiwan (China); Lu, Shao-Chung [Department of Civil Engineering, Chung Yuan Christian University, Chungli, Taiwan (China); Damodar, Rahul A. [Department of Bioenvironmental Engineering, Chung Yuan Christian University, Chungli, Taiwan (China); R and D Center for Membrane Technology, Chung Yuan Christian University, Chungli, Taiwan (China); Wei, Ta-Chin [R and D Center for Membrane Technology, Chung Yuan Christian University, Chungli, Taiwan (China); Department of Chemical Engineering, Chung Yuan Christian University, Chungli, Taiwan (China)

    2012-10-30

    Highlights: Black-Right-Pointing-Pointer Plasma and grafting parameters that maximized TiO{sub 2} binding sites were found. Black-Right-Pointing-Pointer PVDF hydrophilicity was vastly improved compared to other modification techniques. Black-Right-Pointing-Pointer At least 1.5% TiO{sub 2} and 30 min UV exposure were needed to attain full flux recovery. Black-Right-Pointing-Pointer Photocatalytic membranes could remove up to 42% of 50 mg/l RB5 dye. - Abstract: Immobilization of TiO{sub 2} is a promising approach that produces antifouling and photocatalytic membranes that could help advance wastewater treatment and re-use processes. In this study, poly(acrylic acid) (PAA) was plasma-grafted on commercial poly(vinylidene fluoride) (PVDF) to introduce functional groups on the membrane surface that can support the nanoparticles. It was found that plasma treatment at 100 W for 120 s followed by liquid grafting with 70% aqueous AA at 60 Degree-Sign C for 2 h maximized the number of TiO{sub 2} binding sites. Membrane hydrophilicity was tremendously enhanced by the self-assembly of TiO{sub 2}, following a direct proportionality to TiO{sub 2} loading. The membrane with 0.5% TiO{sub 2} loading maintained the highest pure water flux and the best protein antifouling property. UV irradiation triggered the photodegradation of strongly bound foulants, but at least 1.5% TiO{sub 2} and 30 min cumulative irradiation were necessary to completely recover the membrane's original performance. The TiO{sub 2}-modified membranes removed 30-42% of 50 mg/l aqueous Reactive Black 5 (RB5) dye. The fabricated membranes demonstrate huge potential for use in membrane reactors with high hydrophilicity, fouling mitigation, and photocatalytic capability.

  6. Poly(lauryl acrylate) and poly(stearyl acrylate) grafted multiwalled carbon nanotubes for polypropylene composites

    Daugaard, Anders Egede; Jankova Atanasova, Katja; Hvilsted, Søren

    2014-01-01

    , polymerizations of lauryl or stearyl acrylate were performed, resulting in two novel polymer modifications on the MWCNT (poly(lauryl acrylate) or poly(stearyl acrylate)). The method was found to give time dependent loading of polymers as a function of time (up to 38 wt% for both acrylates), and showed a plateau...... were found to be substantially improved, where poly(lauryl acrylate) was found to be the superior surface modification, resulting in a conductive composite....

  7. Technology and the use of acrylics for provisional dentine protection.

    Kapusevska, Biljana; Dereban, Nikola; Popovska, Mirjana; Nikolovska, Julijana; Radojkova Nikolovska, Vеrа; Zabokova Bilbilova, Efka; Mijoska, Aneta

    2013-01-01

    Acrylics are compounds polymerized from monomers of acrylic, metacrylic acid or acrylonitrates. The purpose of this paper is to present the technology and use of acrylics for provisional dentine protection in the practice of dental prosthodontics. For this reason, we followed 120 clinical cases from the everyday clinical practice, divided into 4 groups of 30 patients who needed prosthetic reconstruction. The first group included cases in which we applied celluloid crowns for dentine protection, for the second group we used acrylic teeth from a set of teeth for complete dentures; in the third and fourth groups the fabrication was done with the system of an impression matrix and the acrylic resin block technique respectively. In all the examined patients, the gingival index by Silness and Loe and the vitality of the dental pulp were verified clinically, after preparation and 8 days from the placement of the provisional crown. The value for dental sensitivity measured after preparation was 2.59, and 8 days after the placement of the provisional crown it bwas 3.1. From these results we can conclude that after the 8th day from the placement of the provisional crown, there was an adaptation period, characterized by a decrease in the painful sensations. The value of the Silness and Loe gingival index measured after the preparation was 1.34, and 8 days from the placement of the provisional crown was 0.94. The results inclined us to the fact that the provisional acrylic crowns facilitated the reparation of the periodontal tissue. PMID:24566021

  8. In vitro and in vivo efficacy of doxorubicin loaded biodegradable semi-interpenetrating hydrogel implants of poly (acrylic acid)/gelatin for post surgical tumor treatment

    The paper describes the preparation and evaluation of doxorubicin loaded semi-interpenetrating polymeric hydrogel network of polyacrylic acid (PAc) and gelatin (G). Post surgical antitumor efficacy and biodistribution of doxorubicin from the implanted degradable hydrogels was investigated on Ehrlich's ascites tumor model using albino mice. Polycaprolactone diacrylate (PCL-DAr) was employed as a crosslinking agent for PAc chains whereas G was kept free. The effect of crosslinking concentration on various physico-chemical properties such as thermal behavior, swelling, degradation behavior, drug release and polymer–polymer interactions was investigated by various physico-chemical tools. Semi-interpenetrating polymeric networks (IPNs) with 0.2 mol% crosslinking concentration showed degradation within 20 days in phosphate buffer (pH 6.5). To determine the in vivo anticancer efficacy, placebo and drug laden cylindrical implants (65 ± 5 µg/implant of 10 mg) were implanted in tumor cavity post tumor excision. After predetermined time intervals (day 7, 11, 14, 20 and 25), drug biodistribution was assessed in tumor, tumor periphery, residual hydrogel and all vital organs i.e. liver, spleen, kidney, heart, lung and blood (spectrofluorimetrically). The drug distribution study showed the concentration of drug in the tumor, tumor periphery and residual hydrogel decreased with increasing time; on the 7th day, drug concentration was highest while, on the 25th day, it was negligible; however, insignificant quantities of the drug was found in vital organs. Histological examination revealed no sign of tumor recurrence until the 25th day with 100% necrosis and slight inflammation in treated the group. In vivo results established that these biodegradable implants can be utilized as post surgical therapy for solid tumors. (paper)

  9. Synthesis and properties of photo-curable silicone (meth)acrylate oligomers

    Photo-curable resins are widely used in various applications such as coatings, adhesives and inks, due to their high efficiencies, environmental friendly technology and saving of energy. Silicone (meth) acrylate oligomers offer an excellent slip property because of their low surface tension. In addition, they can enhance other properties like chemical resistance and heat resistance. In this research, photo-curable silicone (meth) acrylate oligomers are prepared from modified PDMS (polydimethyl siloxane) polyols, diisocyanate, carboxylic acid and hydroxyl (meth) acrylate to evaluate basic property of these oligomers. (Author)

  10. Synergistic effect of additives including multifunctional acrylates in wood plastic composites

    Wood Plastic Composite (WPC) was prepared with simul (soft wood, density = 0.4g/cc) and butylmethacrylate (BMA) monomer using 10% methanol as the swelling agent. Effect of additives including multifunctional acrylates such as tripropylene glycol diacrylate (TPGDA), trimethylol propane triacrylate (TMPTA), oligomer acrylates like the urethane (UA), epoxy (EA) and polyester (PEA) acrylates and N-vinyl pyrrolidone (NVP) was investigated using 1 to 3 Mrad dose at 0.8 Mrad/h. Synergistic increases in polymer loading yields was achieved in presence of the additives, particularly with the trifunctional acrylate (TMPTA). In addition, acid as well as urea were also used as co-additives and synergistic enhancement in yields of polymer loading were obtained. The synergistic polymer loading by acid addition causes substantial decrease in tensile strength of the composite; but other additives and co-additives increase both the polymer loading and the tensile strength in these systems. (author)

  11. Electrochemical characterization of aminated acrylic conducting polymer

    New attempt has been made to synthesize aminated acrylic conducting polymer (AACP) using precursor of phenylvinylsulfoxide (PVS). The process was conducted via the integration of microemulsion and photopolymerization techniques. It has been utilized for covalent immobilization of amino groups by the adding of N-achryiloxisuccinimide (NAS). Thermal eliminating of benzene sulfenic acids from PVS has been done at 250 °C to form electroactive polyacetylene (PA) segment. Characterization of AACP has been conducted using fourier transform infrared (FTIR), scanning electron microscopy (SEM) and linear sweep cyclic voltammetry (CV). A range of 0.3-1.25μm particle size obtained from SEM characterization. A quasi-reversible system performed as shown in electrochemical study

  12. Electrochemical characterization of aminated acrylic conducting polymer

    Rashid, Norma Mohammad; Heng, Lee Yook; Ling, Tan Ling

    2015-09-01

    New attempt has been made to synthesize aminated acrylic conducting polymer (AACP) using precursor of phenylvinylsulfoxide (PVS). The process was conducted via the integration of microemulsion and photopolymerization techniques. It has been utilized for covalent immobilization of amino groups by the adding of N-achryiloxisuccinimide (NAS). Thermal eliminating of benzene sulfenic acids from PVS has been done at 250 °C to form electroactive polyacetylene (PA) segment. Characterization of AACP has been conducted using fourier transform infrared (FTIR), scanning electron microscopy (SEM) and linear sweep cyclic voltammetry (CV). A range of 0.3-1.25μm particle size obtained from SEM characterization. A quasi-reversible system performed as shown in electrochemical study.

  13. Electrochemical characterization of aminated acrylic conducting polymer

    Rashid, Norma Mohammad [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Lestari Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor Darul Ehsan (Malaysia); Heng, Lee Yook [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Lestari Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor Darul Ehsan (Malaysia); Southeast Asia Disaster Prevention Research Initiative, Lestari Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor Darul Ehsan (Malaysia); Ling, Tan Ling [Southeast Asia Disaster Prevention Research Initiative, Lestari Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor Darul Ehsan (Malaysia)

    2015-09-25

    New attempt has been made to synthesize aminated acrylic conducting polymer (AACP) using precursor of phenylvinylsulfoxide (PVS). The process was conducted via the integration of microemulsion and photopolymerization techniques. It has been utilized for covalent immobilization of amino groups by the adding of N-achryiloxisuccinimide (NAS). Thermal eliminating of benzene sulfenic acids from PVS has been done at 250 °C to form electroactive polyacetylene (PA) segment. Characterization of AACP has been conducted using fourier transform infrared (FTIR), scanning electron microscopy (SEM) and linear sweep cyclic voltammetry (CV). A range of 0.3-1.25μm particle size obtained from SEM characterization. A quasi-reversible system performed as shown in electrochemical study.

  14. Synthesis and characterization of acrylated epoxidized soybean oil for UV cured coatings

    Habib, Firdous; Bajpai, Madhu

    2011-01-01

    This paper investigates the curing of biodegradable polymer films which were synthesized from soybean oil through the ultraviolet radiation and their stability against thermal degradation. In this study the epoxidation of soybean oil has been carried out via peracetic method. Further, an epoxy acrylate resin was synthesized from the epoxidized soybean oil (ESO) by using acrylic acid monomer. Triethylamine (TEA) and hydroquinone were used as a catalyst and inhibitor respectively. The acrylatio...

  15. Radiation curing silicone acrylate systems

    Radiation curing silicone systems by either ultra violet light (UV) or electron beam (EB) is introduced. The cure is based on the polymerization of the acrylic C = C double bond via a radical chain reaction. In the EB curing process a sufficient number of radicals for spontaneous polymerization is produced due to the high radiation energy whereas with UV light the energy is not as intensive thus a photo-initiator is required for a UV process. The required high local radical concentration provided by its decay. The radical generation immediate chain-growing leads to rapid and efficient crosslinking even at room temperature. It is for this reason that silicone acrylates cure immediately. All coater capable of handling 100% thermally curing silicones are suitable for the use with Goldschmidt's RC systems

  16. Nanocellulose whiskers’dual grafting with acrylic acid and acrylamide for Cu2+ adsorption%纳米纤维素晶须双重接枝共聚物对Cu2+的吸附

    叶代勇; 杨洁

    2014-01-01

    Acrylic acid (AA)and acrylamide (AM)were simultaneously grafted onto the surface of nanocellu-lose whiskers (NCW).The AA,AM-g-NCW was analyzed by infrared spectroscopy (FT-IR)and polarizing op-tical microscopy (POM).The effects of the adsorption time,adsorption temperature,pH values and initial concentration on its Cu2+ adsorption properties were studied.The results showed that AA and AM were suc-cessfully grafted onto the NCW.The added Cu2+ ions influenced the liquid crystalline texture of AA,AM-g-NCW.AA,AM-g-NCW had best adsorption effect for Cu2+ when the adsorption time was 8 h,the adsorption temperature was 35 ℃ and the pH value was 6-8.The maximum adsorption capacity was 38.96 mmol/g for the Cu2+ ions.The adsorption isotherm could be well fitted in with Langmuir equation.%将丙烯酸和丙烯酰胺接枝到纳米纤维素晶须表面,制备出双重接枝共聚物。通过红外光谱和偏光显微镜分析表征双重接枝共聚物的官能团和液晶性能,研究了其对Cu2+的吸附性能,考察了吸附时间、吸附温度、pH 值和初始浓度对吸附性能的影响。实验结果表明,丙烯酸和丙烯酰胺成功接枝到纳米纤维素晶须的表面;Cu2+的加入影响了双重接枝共聚物的液晶织构;在吸附时间为8 h,吸附温度为35℃,pH 值为6~8时,双重接枝共聚物对 Cu2+具有最佳的吸附效果,最大的吸附容量为38.96 mmol/g,吸附过程符合Langmuir方程。

  17. Radiation curing applications of palm oil acrylates

    Various palm oil based urethan acrylate prepolymers (UP) were prepared from palm oil based polyols, diisocyanate compounds and hydroxyl terminated acrylate monomers by following procedure derived from established methods. The products were compared with each other in term of their molecular weights (MW), viscosities, curing speed by UV irradiation, gel contents and film hardness. The molecular structure of diisocyanate compounds and hydroxyl acrylate monomers were tend to determine the molecular weights and hence viscosities of the final products of urethan acrylate prepolymers (UP), whereas, the MW of the UP has no direct effects on the UV curing properties of the prepolymers. (author)

  18. 两性聚羧酸类高聚物阳离子丙烯酸酯单体 DAC 的制备及其性能%Preparation and performance of cationic acrylate monomer (DAC) for amphoteric carboxylic acid polymer

    陈宝璠

    2015-01-01

    以丙烯酸甲酯(MA)与2氯乙醇(CE)为反应原料,通过酯交换反应制备了丙烯酸氯乙醇酯(CA)中间体,再将 CA 与三甲胺(TMA)水溶液反应,合成了一种用于制备两性聚羧酸类高聚物的阳离子丙烯酸酯单体(丙烯酰氧乙基三甲基氯化铵,DAC).采用 FTIR 和1 HNMR 对 DAC 结构进行了表征,并考察了 n(TMA)/n (CA)、催化剂用量、阻聚剂用量、反应温度和反应时间对 CA 转化率和 DAC 质量分数的影响.结果显示:最佳制备工艺条件为 n(TMA)/n(CA)=1.2,催化剂用量为 CA 中间体质量的4.5%,阻聚剂用量为 CA 中间体质量的0.6%,反应温度为50℃,反应时间为3 h.以 DAC 为阳离子单体,与丙烯酸(AA)、聚乙二醇单甲醚丙烯酸酯(MPEGAA)通过反相乳液共聚合制得两性聚羧酸类高聚物,该高聚物具有优异的保坍性和较高的早期抗压强度.%A cationic acrylate monomer,[2-(acryloyloxy)ethyl]trimethyl ammonium chloride,DAC),used for synthetizing amphoteric carboxylic acid polymer was prepared by reaction of 2-chloroethyl acrylate (CA)inter-mediate and trimethylamine (TMA)aqueous solution.The 2-chloroethyl acrylate (CA)intermediate was pre-pared by transesterification of methyl acrylate and 2-chloroethanol.The DAC structure was identified by means of FTIR and 1 HNMR.The influences of n (TMA)/n (CA),dosages of catalyst and polymerization inhibitor,reaction temperature and reaction time were investigated with the conversion rate of CA and mass fraction of DAC.The results show that the optimal technological conditions for the preparation includes:n(TMA)/n(CA)is 1.2,the dosage of catalyst is 4.5% and the dosage of polymerization inhibitor is 0.6%according to the mass of CA,the reaction temperature is 50 ℃ and the reaction time is 3 h.And the amphoter-ic carboxylic acid polymer was prepared by means of inverse emulsion copolymerization of DAC,acrylic

  19. Surface modification of nanoparticles for radiation curable acrylate clear coatings

    Bauer, F.; Gläsel, H.-J.; Hartmann, E.; Bilz, E.; Mehnert, R.

    2003-08-01

    To obtain transparent, scratch and abrasion resistant coatings a high content of nanosized silica and alumina filler was embedded in radiation-curable acrylate formulations by acid catalyzed silylation using trialkoxysilanes. 29SiMAS NMR and MALDI-TOF mass spectrometry were employed to elucidate the structure of the surface-grafted methacryloxypropyl-, vinyl- and n-propyl-trimethoxysilane. In accordance with NMR findings, MALDI-TOF MS showed highly condensed oligomeric siloxanes of more than 20 monomeric silane units. A ladder-like structure of bound polysiloxanes is proposed rather than a simplified picture of tridentate silane bonding. Hence, silane coupling agents do not only modify the chemical nature of the filler surface but also strongly effect the rheological properties of the acrylate nanodispersions.

  20. Radiation cross-linking of epoxide-acrylic compositions

    The process of hardening of epoxy-acryl compositions on copper, aluminium, iron, and glass substrates has been studied under the action of ionizing radiation (accelerated electrons, γ-radiation). Irradiated samples have been heat treated for 2 hours at 100 and 150 deg C for accelerating posteffect. In the epoxy oligomer-acrylic acid system structurization is completed at a dose of 10-12 Mrad. The content of gel fraction equals 30-62% when irradiation is performed in air and up to 85% when the samples are irradiated under film. The effect has been established of natural epoxy oligomers and various plasticizers on the structurization process. The possibility has been shown of obtaining heat-resistant coatings based on epoxy oligomers

  1. Surface modification of nanoparticles for radiation curable acrylate clear coatings

    To obtain transparent, scratch and abrasion resistant coatings a high content of nanosized silica and alumina filler was embedded in radiation-curable acrylate formulations by acid catalyzed silylation using trialkoxysilanes. 29SiMAS NMR and MALDI-TOF mass spectrometry were employed to elucidate the structure of the surface-grafted methacryloxypropyl-, vinyl- and n-propyl-trimethoxysilane. In accordance with NMR findings, MALDI-TOF MS showed highly condensed oligomeric siloxanes of more than 20 monomeric silane units. A ladder-like structure of bound polysiloxanes is proposed rather than a simplified picture of tridentate silane bonding. Hence, silane coupling agents do not only modify the chemical nature of the filler surface but also strongly effect the rheological properties of the acrylate nanodispersions

  2. Preparation and reactivity of metal-containing monomers. Communication 3. Radiation graft polymerization of Co(II), Ni(II), and Cu(II) acrylates on polyethylene

    Graft polymerization of Co(II), Ni(II), and Cu(II) acrylates was carried out on polyethylene powder subjected to prior irradiation in the air and graft copolymers were obtained with up to 1.4 mass % metal content. The graft polymerization of metal acrylates on polyethylene proceeds 10 times more slowly than in the case of acrylic acid with virtually the complete absence of thermal homopolymerization. The graft rate is independent of the concentration of the metal-containing monomer in the range from 1 to 10 mass %. The graft polymerization of acrylates is initiated by radicals formed as a result of the decomposition of the hydroperoxide groups with subsequent predominantly bimolecular termination of the growing polymer chains in the case of Co(II) and Ni(II) acrylates and monomolecular termination in the case of Cu(II) acrylate. The effective activation energies for the graft polymerization reactions were determined

  3. Synthesis and Antibacterial Activity of the Carboxymethyl Chitosan Graft Poly(Acrylic Acid)Superabsorbent Resins%羧甲基壳聚糖接枝聚丙烯酸高吸水树脂的制备及抑菌性能

    王开明; 黄惠莉; 王忠敏

    2012-01-01

    以壳聚糖为原料,在碱性条件下与氯乙酸反应,合成了具有良好水溶性的羧甲基壳聚糖.以合成的水溶性羧甲基壳聚糖和丙烯酸为原料,通过接枝共聚反应合成了具有一定抑菌性能的羧甲基壳聚糖接枝聚丙烯酸高吸水树脂.探讨了羧甲基壳聚糖的合成条件,研究了羧甲基壳聚糖用量对树脂吸水性能和抑菌性能的影响.结果表明,当碱与壳聚糖的质量比为6:1,氯乙酸与壳聚糖的质量比为5.5:1时,羧甲基壳聚糖的产率和取代度均较高,在水中的水溶性较好;在相同的合成条件下,当羧甲基壳聚糖用量为丙烯酸质量的1.80%时,树脂具有较高的吸水性能及良好的抑菌性能,且均优于壳聚糖接枝聚丙烯酸高吸水树脂,其吸水倍率为980 g/g,对大肠杆菌和金黄色葡萄球菌均有抑制其生长的作用,抑菌率分别为91.7%和70.6%.%The carboxymethyl chitosan which had good water-solubility was synthesized by the reaction between chitosan and chloroacetic acid under alkaline condition. After that, a series of carboxymethyl chitosan graft poly ( acrylic acid ) superabsorbent resins which had antibacterial activity were synthesized by graft polymerization between carboxymethyl chitosan and acrylic acid. The synthesis conditions of carboxymethyl chitosan were investigated, the effects of carboxymethyl chitosan content on the water absorbency and antibacterial activity of the superabsorbent resins were studied. The result showed that when the mass ratio of alkali to carboxymethyl chitosan was 6:1 and the mass ratio of chloroacetic acid to carboxymethyl chitosan was 5.5:1, the carboxymethyl chitosanthe had good yield and degree of substitution. Under the same conditions of synthesis, when the content of carboxymethyl chitosan was 1.8% of acrylic acid mass, the superabsorbent resin had better water absorbency and antibacterial activity, moreover, which were higher than chitosan graft poly ( acrylic acid

  4. Study on the Protein Diffusion Behavior in the Poly(Acrylamide-co-Acrylic Acid) Copolymer by FRAP Technique%应用FRAP技术评价蛋白在聚丙烯酰胺-丙烯酸凝胶中的扩散行为

    崔金磊; 周稳稳; 邱玉琴; 高云华

    2011-01-01

    The drug release behavior from the carrier is bound up with the carrier s structure. In this paper, a series of poly (acrylamide-co-acrylic acid) hydrogels with different acrylamide/ acrylic acid ratios have been successfully synthesized by aqueous polymerization. These co-polymers were characterized with FTIR technique to confirm the co-polymer formation. Fluorescence recovery after photobleaching (FRAP) technique was used to investigate the diffusion behavior of fluorescein isothiocyanate labelled bovine serum albumin (FITC-BSA) in these co-polymer hydrogels? And a confocal laser scanning microscopy was applied to obtain high resolution images in real time. The results showed that the diffusion coefficient of FITC-BSA was influenced by the ratio between the acrylamide and acrylic acid in co-polymer and the co-polymer hydrogels synthesized may have potential application in controlled protein delivery system.%药物分子从药物载体中的释放行为与载体的结构有密切关系.本实验中采用丙烯酰胺和丙烯酸等材料,运用水相沉淀的方法,制备了4种不同单体配比的聚丙烯酰胺-丙烯酸(P(Am-co-Ac)共聚物水凝胶.运用红外分析方法对P (Am-co-Ac)组成进行表征.使用荧光漂白恢复法(FRAP,fluorescence recovery after photobleaching)观察荧光素FITC标记的牛血清白蛋白(BSA)在聚丙烯酰胺-丙烯酸中的扩散行为,并以激光共聚焦显微镜进行实时成像.实验表明,FITC-BSA在不同单体配比的共聚物中的扩散系数是不同的.通过调节聚合物中单体的配比能够达到控制蛋白释放速率的作用,从而为调控蛋白和多肽类药物的缓控释放提供了可能性.

  5. Radiopurity measurement of acrylic for DEAP-3600

    The spherical acrylic vessel that contains the liquid argon target is the most critical detector component in the DEAP-3600 dark matter experiment. Alpha decays near the inner surface of the acrylic vessel are one of the main sources of background in the detector. A fraction of the alpha energy, or the recoiling nucleus from the alpha decay, could misreconstruct in the fiducial volume and result in a false candidate dark matter event. Acrylic has low levels of inherent contamination from 238U and 232Th. Another background of particular concern is diffusion of 222Rn during manufacturing, leading to 210Pb contamination. The maximum acceptable concentrations in the DEAP-3600 acrylic vessel are ppt levels of 238U and 232Th equivalent, and 10−8 ppt 210Pb. The impurities in the bulk acrylic will be measured by vaporizing a large quantity of acrylic and counting the concentrated residue with ultra-low background HPGe detectors and a low background alpha spectrometer. An overview of the acrylic assay technique is presented

  6. Radiopurity measurement of acrylic for DEAP-3600

    Nantais, C. M.; Boulay, M. G. [Department of Physics, Engineering Physics, and Astronomy, Queen' s University, Kingston, Ontario K7L 3N6 (Canada); Cleveland, B. T. [SNOLAB, Lively, Ontario P3Y 1N2 Canada and Department of Physics, Laurentian University, Sudbury, Ontario P3E 2C6 (Canada)

    2013-08-08

    The spherical acrylic vessel that contains the liquid argon target is the most critical detector component in the DEAP-3600 dark matter experiment. Alpha decays near the inner surface of the acrylic vessel are one of the main sources of background in the detector. A fraction of the alpha energy, or the recoiling nucleus from the alpha decay, could misreconstruct in the fiducial volume and result in a false candidate dark matter event. Acrylic has low levels of inherent contamination from {sup 238}U and {sup 232}Th. Another background of particular concern is diffusion of {sup 222}Rn during manufacturing, leading to {sup 210}Pb contamination. The maximum acceptable concentrations in the DEAP-3600 acrylic vessel are ppt levels of {sup 238}U and {sup 232}Th equivalent, and 10{sup −8} ppt {sup 210}Pb. The impurities in the bulk acrylic will be measured by vaporizing a large quantity of acrylic and counting the concentrated residue with ultra-low background HPGe detectors and a low background alpha spectrometer. An overview of the acrylic assay technique is presented.

  7. Occupational respiratory disease caused by acrylates.

    Savonius, B; Keskinen, H; Tuppurainen, M; Kanerva, L

    1993-05-01

    Acrylates are compounds used in a variety of industrial fields and their use is increasing. They have many features which make them superior to formerly used chemicals, regarding both their industrial use and their possible health effects. Contact sensitization is, however, one of their well known adverse health effects but they may also cause respiratory symptoms. We report on 18 cases of respiratory disease, mainly asthma, caused by different acrylates, 10 cases caused by cyanoacrylates, four by methacrylates and two cases by other acrylates. PMID:8334539

  8. The development of palm oil based acrylated resins and their applications

    Since Malaysia provides 57 and 75% of the world's production and exports of palm oil respectively, it is natural that we should be in the forefront of the research of widening the use of palm oil in oleochemicals industry, which are currently increase in popularity. The presence of unsaturation in the fatty acids of vegetable oils such as palm oil, technically paves the way for the production of acrylated resins. The more unsaturated the oil, the better it will perform in the radiation curing related applications. The first acrylated palm oil was synthesised in early 1989, through acrylation process, whereby, acrylic acid is introduced into oxirane group of the epoxidised palm oil products, EPOP, at 100-130 deg C in the presence of triethylamine, TEA, as a catalyst and 4-methoxyphenol as an inhibitor. The acrylated products namely epoxidised palm oil (olein) acrylate, EPOLA/EPOPA, was found curable when subjected to UV or EB irradiations. The EPOLA based formulated resins were satisfactorily been used as radiation curable coating materials on various substrates such as woods, bamboos, glass, ceramics and metals without any major defects at reasonably fast cure rate. Preliminary investigations also revealed their potentials as radiation curable pressure sensitive adhesives and printing inks. Isocyanation of EPOLAs at 50 to 90deg C with the presence of 1% inhibitor such as 4-methoxyphenol resulted in resins called Palm oil based urethane acrylates, POBUA. This newly synthesised resins possess certain advantages over EPOLA such as higher molecular weight, better crosslinking density, abrasion resistance, tensile properties and also pendulum hardness. Early results might suggest that POBUA is in a better position to be used as resins for radiation curing of surface coating applications

  9. Resistance of acrylic vessel to gamma irradiation

    This paper describes the preliminary studies made in acrylic material in order to verify the effects of radiolysis in acrylic recipients in which the uranium ore standards are conditioned and check if the material is able to keep the 222Rn inside the vessel. The preliminary results after gamma irradiation of two kinds of recipients indicate no differences between the vessels irradiated and the ones no irradiated, related to color changes and tension resistance. (author)

  10. Rapid Output Growth of Special Acrylic Esters

    Wang Lianzhi

    2007-01-01

    @@ Acrylic esters are usually classified into general-purpose varieties and special varieties. The production and application of general-purpose varieties is already quite matured in the world and their output growth tends to be flat. Owing to the development of coatings, electronics, automobiles,textiles, printing and construction sectors, especially the application of radiation curing technology in various sectors, special acrylic esters have developed rapidly.

  11. Resistance of acrylic vessel to gamma irradiation

    Carneiro, Andre Cavalcanti; Menezes, Maria Angela de B.C.; Pereira, Marcio Tadeu; Rocha, Nirlando Antonio; Vilela, Jefferson Jose, E-mail: andreccarneiro@gmail.com, E-mail: menezes@cdtn.br, E-mail: mtp@cdtn.br, E-mail: nar@cdtn.br, E-mail: jjv@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Braga, Mario Roberto Martins S.S., E-mail: mariomartins@gmail.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Programa de Pos-Graduacao em Ciencias e Tecnicas Nucleares

    2013-07-01

    This paper describes the preliminary studies made in acrylic material in order to verify the effects of radiolysis in acrylic recipients in which the uranium ore standards are conditioned and check if the material is able to keep the {sup 222}Rn inside the vessel. The preliminary results after gamma irradiation of two kinds of recipients indicate no differences between the vessels irradiated and the ones no irradiated, related to color changes and tension resistance. (author)

  12. Gel time of calcium acrylate grouting material.

    Han, Tong-Chun

    2004-08-01

    Calcium acrylate is a polymerized grout, and can polymerize in an aqueous solution. The polymerization reaction utilizes ammonium persulfate as a catalyst and sodium thiosulfate as the activator. Based on the theory of reaction kinetics, this study on the relation between gel time and concentration of activator and catalyst showed that gel time of calcium acrylate is inversely proportional to activator and catalyst concentration. A formula of gel time is proposed, and an example is provided to verify the proposed formula. PMID:15236477

  13. Multi-functional hybrid coatings containing silica nanoparticles and anti-corrosive acrylate monomer for scratch and corrosion resistance

    Multi-functional hybrid coatings having both anti-corrosion and scratch resistance were prepared from modified silica nanoparticles and functional acrylates. To improve the dispersion properties of silica nanoparticles in the organic/inorganic hybrid coatings, the surface of the nanoparticles was modified with γ-methacryloxypropyltrimethoxysilane. The coating solution could be prepared by mixing modified silica nanoparticles, tetrasiloxane acrylate, di-acrylate monomer containing an anti-corrosion functional group, acrylic acid, and an initiator in a solvent. The mixture was then dip-coated on iron substrates and finally polymerized by ultraviolet (UV) irradiation. Corrosion and scratch resistance of the coated iron was evaluated by electrochemical impedance spectroscopy (EIS) and a pencil hardness test, respectively. From the EIS results, the coatings with tetrasiloxane acrylate and di-acrylate did not show any decrease in impedance or phase angle, even after 50 days' exposure to 0.1 M NaCl electrolyte, whereas the conventional acrylate coatings started to fail after only 24 h. A hybrid coating containing the amine-quinone functional group exhibited excellent corrosion protection properties with 4-5H pencil hardness.

  14. Multi-functional hybrid coatings containing silica nanoparticles and anti-corrosive acrylate monomer for scratch and corrosion resistance

    Seo, Ji Yeon; Han, Mijeong

    2011-01-01

    Multi-functional hybrid coatings having both anti-corrosion and scratch resistance were prepared from modified silica nanoparticles and functional acrylates. To improve the dispersion properties of silica nanoparticles in the organic/inorganic hybrid coatings, the surface of the nanoparticles was modified with γ-methacryloxypropyltrimethoxysilane. The coating solution could be prepared by mixing modified silica nanoparticles, tetrasiloxane acrylate, di-acrylate monomer containing an anti-corrosion functional group, acrylic acid, and an initiator in a solvent. The mixture was then dip-coated on iron substrates and finally polymerized by ultraviolet (UV) irradiation. Corrosion and scratch resistance of the coated iron was evaluated by electrochemical impedance spectroscopy (EIS) and a pencil hardness test, respectively. From the EIS results, the coatings with tetrasiloxane acrylate and di-acrylate did not show any decrease in impedance or phase angle, even after 50 days' exposure to 0.1 M NaCl electrolyte, whereas the conventional acrylate coatings started to fail after only 24 h. A hybrid coating containing the amine-quinone functional group exhibited excellent corrosion protection properties with 4-5H pencil hardness.

  15. Property Research of Instant Polymerization Acrylate Size Mixture%瞬时聚合丙烯酸酯浆料的性能研究

    吴长春; 武海良; 沈艳琴; 杨微

    2011-01-01

    探讨在采用瞬时聚合法直接合成固体丙烯酸酯浆料的过程中,疏水性单体丙烯酸丁酯用量对所生成丙烯酸酯浆料性能的影响.测试了不同丙烯酸丁酯用量下反应生成物的水溶性、水溶液黏度及对涤棉粗纱黏附性,并对合成的固体丙烯酸浆料进行红外表征.结果表明:在丙烯酸的中和度为50%、氧化还原引发体系中引发剂为单体量的6%时,丙烯酸丁酯为单体量的25%时合成的浆料性能最好,所生产的浆料为丙烯酸-丙烯酸钠盐-丙烯酸丁酯共聚物.%Effect of hydrophobic monomer butyl acrylate amount on acrylate size mixture property in the process of compounding solid acrylate size mixture directly by instant polymerization was discussed. Water-soluble, solution viscosity and adhesion to polyester cotton roving of polymer were tested in condition of different butyl acrylate amount. Infrared spectroscopy was done on solid acrylate size mixture. The result shows that property of the acrylate size mixture is the best,the size mixture is acrylate,acrylic acid,butyl acrylate copolymer when acrylic acid neutralization degree is 50% ,initiator content in redox initiation system is 6% ,butyl acrylate is 25%.

  16. [MORPHOLOGICAL FEATURES OF RAT MUCOUS MEMBRANE OF THE TONGUE EARLY AFFECTED BY ACRYLIC RESIN MONOMER].

    Davydenko, V; Nidzelskiy, M; Starchenko, I; Davydenko, A; Kuznetsov, V

    2016-03-01

    Base materials, made on the basis of various derivatives of acrylic and methacrylic acids, have been widely used in prosthetic dentistry. Free monomer, affecting the tissues of prosthetic bed and the whole body, is always found in dentures. Therefore, study of the effect of acrylic resins' monomer on mucous membrane of the tongue is crucial. Rat tongue is very similar to human tongue, and this fact has become the basis for selecting these animals to be involved into the experiment. The paper presents the findings related to the effect of "Ftoraks" base acrylic resin monomer on the state of rat mucous membrane of the tongue and its regeneration. The microscopy has found that the greatest changes in the mucous membrane of the tongue occur on day 3 and 7 day after applying the monomer and are of erosive and inflammatory nature. Regeneration of tongue epithelium slows down. PMID:27119844

  17. New blends of ethylene-butyl acrylate copolymers with thermoplastic starch. Characterization and bacterial biodegradation.

    Morro, A; Catalina, F; Corrales, T; Pablos, J L; Marin, I; Abrusci, C

    2016-09-20

    Ethylene-butyl acrylate copolymer (EBA) with 13% of butyl acrylate content was used to produce blends with 10, 30 and 60% of thermoplastic starch (TPS) plasticized with glycerol. Ethylene-acrylic acid copolymer (EAA) was used as compatibilizer at 20% content with respect to EBA. The blends were characterized by X-ray diffraction, ATR-Fourier Transform Infrared Spectroscopy (ATR-FTIR), Scanning Electron Microscopy (SEM), water-Contact Angle measurements (CA), Differential Scanning Calorimetry (DSC) and Stress-strain mechanical tests. Initiated autoxidation of the polymer blends was studied by chemiluminescence (CL) confirming that the presence of the polyolefin-TPS interphase did not substantially affect the oxidative thermostability of the materials. Three bacterial species have been isolated from the blend films buried in soil and identified as Bacillus subtilis, Bacillus borstelensis and Bacillus licheniformis. Biodegradation of the blends (28days at 45°C) was evaluated by carbon dioxide measurement using the indirect impedance technique. PMID:27261731

  18. Photochemistry of Acrylates at 222 nm

    Excimer lamps as monochromatic UV sources with an intense short wavelength mission (specially Kr Cl, 222 nm) allow a photo initiator-free initiation of the acrylate polymerisation. Laser photolysis (Kr Cl excimer laser, pulse width 20 ns, up to 5 ml per pulse) gives rise to similar transient spectra (max << 280 nm) for all acrylates studied. As the rather unspecific spectra do not allow conclusions as to the main reaction channel, a product study has been performed by GC-MS following steady-state photolysis of acrylate solutions in acetonitrile, methanol and n-hexane. Somewhat unexpected, a-cleavage seems to be a main reaction channel, and quantum chemical calculations show that such a reaction can occur from either the excited singlet state or the un relaxed triplet state, but not from the relaxed triplet state that is observed spectroscopically. A reaction scheme accounting for the observed products is presented

  19. Concepts for stereoselective acrylate insertion

    Neuwald, Boris

    2013-01-23

    Various phosphinesulfonato ligands and the corresponding palladium complexes [{((PaO)PdMeCl)-μ-M}n] ([{( X1-Cl)-μ-M}n], (PaO) = κ2- P,O-Ar2PC6H4SO2O) with symmetric (Ar = 2-MeOC6H4, 2-CF3C6H4, 2,6-(MeO)2C6H3, 2,6-(iPrO)2C 6H3, 2-(2′,6′-(MeO)2C 6H3)C6H4) and asymmetric substituted phosphorus atoms (Ar1 = 2,6-(MeO)2C6H 3, Ar2 = 2′-(2,6-(MeO)2C 6H3)C6H4; Ar1 = 2,6-(MeO)2C6H3, Ar2 = 2-cHexOC 6H4) were synthesized. Analyses of molecular motions and dynamics by variable temperature NMR studies and line shape analysis were performed for the free ligands and the complexes. The highest barriers of ΔGa = 44-64 kJ/mol were assigned to an aryl rotation process, and the flexibility of the ligand framework was found to be a key obstacle to a more effective stereocontrol. An increase of steric bulk at the aryl substituents raises the motional barriers but diminishes insertion rates and regioselectivity. The stereoselectivity of the first and the second methyl acrylate (MA) insertion into the Pd-Me bond of in situ generated complexes X1 was investigated by NMR and DFT methods. The substitution pattern of the ligand clearly affects the first MA insertion, resulting in a stereoselectivity of up to 6:1 for complexes with an asymmetric substituted phosphorus. In the consecutive insertion, the stereoselectivity is diminished in all cases. DFT analysis of the corresponding insertion transition states revealed that a selectivity for the first insertion with asymmetric (P aO) complexes is diminished in the consecutive insertions due to uncooperatively working enantiomorphic and chain end stereocontrol. From these observations, further concepts are developed. © 2012 American Chemical Society.

  20. Occupational fingertip eczema from acrylates in a manicurist

    Denitza Zheleva; Razvigor Darlenski

    2015-01-01

    Occupational hand eczema due to acrylates present in the workplace is a disease frequently reported among dentists, printers, and fiberglass workers. Acrylate monomers are used in the production of a great variety of polymers, including nail cosmetics. Our case report demonstrates a rare clinical presentations of allergic contact dermatitis from acrylic nails. Our patient was working as a manicurist and the diagnostic analyses revealed sensitation to some of the (meth) acrylate compounds of h...

  1. 21 CFR 175.210 - Acrylate ester copolymer coating.

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylate ester copolymer coating. 175.210 Section... COATINGS Substances for Use as Components of Coatings § 175.210 Acrylate ester copolymer coating. Acrylate ester copolymer coating may safely be used as a food-contact surface of articles intended for...

  2. 40 CFR 721.324 - Alkoxylated acrylate polymer (generic).

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkoxylated acrylate polymer (generic... Substances § 721.324 Alkoxylated acrylate polymer (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkoxylated acrylate...

  3. SYNTHESIS OF BIOCOMPATIBLE ACRYLIC POLYMERS HAVING ASPIRIN-MOIETIES

    LI Fumian; GU Zhongwei; FENG Xinde(S. T. Voong)

    1983-01-01

    Several new monomers, β-(acetylsalicylyloxy)ethyl methacrylate, β-(acetylsalicylyloxy)propyl methacrylate, β-(acetylsalicylyloxy)ethyl acrylate, β-hydroxy-γ-(acetylsalicylyloxy)propyl methacrylate, β-hydroxy-γ-(acetylsalicylyloxy)propyl acrylate have been synthesized from aspirin with corresponding hydroxyalkyl or glycidyl acrylates, and then polymerized by free radical initiator.

  4. 40 CFR 721.5325 - Nickel acrylate complex.

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Nickel acrylate complex. 721.5325... Substances § 721.5325 Nickel acrylate complex. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance nickel acrylate complex (PMN P-85-1034) is subject to reporting...

  5. Probing the cooperative dynamics varying the side-chain length of poly(alkyl acrylate)s: ESR experiments

    Andreozzi, Laura; Autiero, Ciro; Faetti, Massimo; Giordano, Marco; Zulli, Fabio

    2007-01-01

    Abstract The rotational dynamics of the tracer cholestane dissolved in unentangled nearly monodisperse poly(alkyl acrylate) melts has been investigated by means of electron spin resonance spectroscopy. Three samples of almost same molecular weight were selected, poly(methyl acrylate) poly(ethyl acrylate) and poly(n-butyl acrylate), whose linear viscoelastic properties were also characterised. Large temperature intervals were found with power laws relating shear flow relaxation and ...

  6. Thermodynamic Interactions between Polystyrene and Long-Chain Poly(n-Alkyl Acrylates) Derived from Plant Oils.

    Wang, Shu; Robertson, Megan L

    2015-06-10

    Vegetable oils and their fatty acids are promising sources for the derivation of polymers. Long-chain poly(n-alkyl acrylates) and poly(n-alkyl methacrylates) are readily derived from fatty acids through conversion of the carboxylic acid end-group to an acrylate or methacrylate group. The resulting polymers contain long alkyl side-chains with around 10-22 carbon atoms. Regardless of the monomer source, the presence of alkyl side-chains in poly(n-alkyl acrylates) and poly(n-alkyl methacrylates) provides a convenient mechanism for tuning their physical properties. The development of structured multicomponent materials, including block copolymers and blends, containing poly(n-alkyl acrylates) and poly(n-alkyl methacrylates) requires knowledge of the thermodynamic interactions governing their self-assembly, typically described by the Flory-Huggins interaction parameter χ. We have investigated the χ parameter between polystyrene and long-chain poly(n-alkyl acrylate) homopolymers and copolymers: specifically we have included poly(stearyl acrylate), poly(lauryl acrylate), and their random copolymers. Lauryl and stearyl acrylate were chosen as model alkyl acrylates derived from vegetable oils and have alkyl side-chain lengths of 12 and 18 carbon atoms, respectively. Polystyrene is included in this study as a model petroleum-sourced polymer, which has wide applicability in commercially relevant multicomponent polymeric materials. Two independent methods were employed to measure the χ parameter: cloud point measurements on binary blends and characterization of the order-disorder transition of triblock copolymers, which were in relatively good agreement with one another. The χ parameter was found to be independent of the alkyl side-chain length (n) for large values of n (i.e., n > 10). This behavior is in stark contrast to the n-dependence of the χ parameter predicted from solubility parameter theory. Our study complements prior work investigating the interactions between

  7. Avaliação da interação macromolécula/íon Zn+2 em meio aquoso: poli(acrilamida-co-ácido acrílico e taninos Estimation of the macromolecules/zinc ion interaction in the aqueous solution: poly(acrylamide-co-acrylic acid and tannins

    Márcia D. Clarisse

    2000-09-01

    Full Text Available Este trabalho visa o estudo da interação entre polímeros sintéticos e produtos naturais à base de taninos com o íon zinco (Zn+2 em meio aquoso para sua utilização na remoção de metais em efluentes. Uma série de copolímeros poli(acrilamida-co-ácido acrílico de diferentes composições e homopolímeros de acrilamida e de ácido acrílico foram preparados, assim como, taninos comerciais foram utilizados como recebidos e purificados por extração. Uma metodologia de avaliação da eficiência de interação da macromolécula com o íon Zn+2 foi desenvolvida baseada em curva padrão de intensidade de absorção na região do ultravioleta-visível (UV-VIS em função da concentração do complexo formado, utilizando colorimetria. A capacidade de interação com o íon zinco foi ligeiramente maior para os polímeros sintéticos porém o produto natural tem a vantagem de apresentar um custo mais baixo.The aim of this work was to evaluate the interaction between natural and synthetic macromolecules with the zinc ion (Zn+2 in aqueous solution. Polyacrylamide, poly(acrylic acid and poly(acrylamide-co-acrylic acid were prepared and natural products (tannins were extracted and purified from commercial products. The methodology to evaluate the macromolecule/zinc ion interaction was based on colorimetry by using a standard curve. The interaction efficiency was slightly larger for the synthetic macromolecules when compared to the natural one. Nevertheless, the tanning has lower cost and its use could be recommended.

  8. 羧甲基纤维素接枝丙烯酸/丙烯酰胺缓释肥包膜材料的制备、性能及应用%Preparation of Carboxymethyl Cellulose Graft Acrylic Acid/Acrylamide and Its Application to Coated Urea Slow Release Fertilizer

    徐浩龙

    2012-01-01

    以过硫酸钾为引发剂、N,N'-亚甲基双丙烯酰胺为交联剂,采用水溶液聚合法制备了羧甲基纤维素接枝丙烯酸/丙烯酰胺缓释肥包膜材料,对其吸水性及耐盐性进行了检测,并将其应用于包膜尿素缓释肥的制备.结果表明,在羧甲基纤维素与丙烯酸质量比为3:17、丙烯酰胺用量为12%时,所制备包膜材料在去离子水、自来水和0.4%盐水中的吸水率分别达到743 g.g-1、497 g·g-1和329 g·g-1;包膜尿素缓释肥的氮素释放率满足GB/T 23348- 2009要求,缓释周期达63 d.%Carboxymethyl cellulose graft acrylic acid/acrylamide was prepared by the method of graft copolymerization using potassium persulfate as initiator and N,N'-methylenebisacrylamide as crosslinking agent. The water absorption and salt tolerance of the coating material were determined,and it was applied to preparation of coated urea slow release fertilizer. When the mass ratio of carboxymethyl cellulose to acrylic acid was 3 : 17 and the amount of acrylamide was 12%,the water absorption rate of the coating material was 743 g · g-1,497 g · g-l ,329 g · g-1 in deionized water,tap water,and 0. 4% brine,respectively. The slow-release period of coated urea was 63 d with the nitrogen release rate meeting the standard GB/T-23348-2009.

  9. Characteristics and mechanisms of acrylate polymer damage to maize seedlings.

    Chen, Xian; Mao, Xiaoyun; Lu, Qin; Liao, Zongwen; He, Zhenli

    2016-07-01

    Superabsorbent acrylate polymers (SAPs) have been widely used to maintain soil moisture in agricultural management, but they may cause damage to plants, and the mechanisms are not well understood. In this study, seed germination, soil pot culture, hydroponic experiments, and SAPs degradation were conducted to investigate damage characteristics and mechanisms associated with SAPs application. The Results showed that SAPs inhibited maize growth and altered root morphology (irregular and loose arrangement of cells and breakage of cortex parenchyma), and the inhibitory effects were enhanced at higher SAPs rates. After 1h SAP hydrogels treatment, root malondialdehyde (MDA) content was significantly increased, while superoxide dismutase (SOD) and catalase (CAT) content were significantly decreased. Hydroponics experiment indicated that root and shoot growth was inhibited at 2.5mgL(-1) acrylic acid (AA), and the inhibition was enhanced with increasing AA rates. This effect was exacerbated by the presence of Na(+) at a high concentration in the hydrogels. Release and degradation of AA were enhanced at higher soil moisture levels. A complete degradation of AA occurred between 15 and 20 days after incubation (DAI), but it took longer for Na(+) concentration to decrease to a safe level. These results indicate that high concentration of both AA and Na(+) present in the SAPs inhibits plant growth. The finding of this study may provide a guideline for appropriate application of SAPs in agriculture. PMID:27057990

  10. Role of leucine in isoprenoid metabolism. Incorporation of (3-/sup 13/C)leucine and of (2-/sup 3/H,4-/sup 14/C)-. beta. ,. beta. -dimethyl-acrylic acid into phytosterols by tissue cultures of Andrographis paniculata

    Anastasis, P.; Freer, I.; Overton, K.; Rycroft, D.; Singh, S.B. (Glasgow Univ. (UK). Dept. of Chemistry)

    1985-02-01

    (3-/sup 13/C)Leucine is incorporated into phytosterols by tissue cultures of Andrographis paniculata by breakdown to acetyl-CoA and its subsequent incorporation via (3S)-3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) and mevalonic acid; (2-/sup 3/H,4-/sup 14/C)-..beta..,..beta..-dimethylacrylic acid also is not incorporated intact.

  11. UV-Curing of Nanoparticle Reinforced Acrylates

    Polymer reinforcement by silica and alumina nanoparticles evidently yields improved surface hardness. Single mixing of nanoparticles into an acrylate formulations, however, leads to highly viscous solutions inappropriate for coating procedures. The incompatibility of inorganic fillers and organic polymers can be avoided by surface modification providing an interface between the two dissimilar materials. For example, vinyltrimethoxysilane (VTMO) can react via hydrolysis/condensation reactions with hydroxyl groups present on the inorganic surface and should bond via the polymerisation-active vinyl group to an acrylate resin through crosslinking reactions. Grafting reactions of surface OH groups and different trialkoxysilanes were studied by thermogravimetry, infrared, and multinuclear NMR spectroscopy. The copolymeri-zation of modified nanoparticles with the acrylate matrix has been investigated by 13C NMR spectroscopy. UV curing under nitrogen inertization revealed a lower reactivity of vinyl groups of VTMO-modified silica compared to grafted methacryloxypropyl-trimethoxysilane (MEMO) which showed complete conversion of olefinic carbons (signals at 120 - 140 ppm). Under conditions of oxygen inhibition, the effect of the kind and the concentration of photoinitiator on the photopoly-merization reaction was studied. Compared to neat polyacrylate coatings the nanocomposite materials exhibit markedly improved properties, e.g., heat, scratch, and abrasion resistance. However, a much better abrasion resistance was obtained for coatings containing both silica nano-particles and corundum microparticles. In particular cases, radiation curing with 172 nm photons generated by Xe excimer was performed to obtain structured polymer surfaces, i.e., matting of the reinforced acrylate coatings

  12. Thermal Polymerization of N-Butyl Acrylate

    Ingham, J. D.

    1982-01-01

    Simple new polymerization method enables production of n-butyl acrylate polymer of desired high molecular weight, without disadvantages that usually attend more conventional methods. Process, which is hybrid of thermal, solution, and emulsion polymerization methods, involves controlled thermal polymerization of monomer at moderate temperatures without use of catalysts or additives.

  13. Acrylic Tanks for Stunning Chemical Demonstrations

    Mirholm, Alexander; Ellervik, Ulf

    2009-01-01

    We describe the use of acrylic tanks (400 x 450 x 27 mm) for visualization of chemical demonstrations in aqueous solutions. Examples of well-suited demonstrations are oscillating reactions, pH indicators, photochemical reduction of Lauth's violet, and chemoluminiscent reactions. (Contains 1 figure.)

  14. Large Acrylic Spherical Windows In Hyperbaric Underwater Photography

    Lones, Joe J.; Stachiw, Jerry D.

    1983-10-01

    Both acrylic plastic and glass are common materials for hyperbaric optical windows. Although glass continues to be used occasionally for small windows, virtually all large viewports are made of acrylic. It is easy to uderstand the wide use of acrylic when comparing design properties of this plastic with those of glass, and glass windows are relatively more difficult to fabricate and use. in addition there are published guides for the design and fabrication of acrylic windows to be used in the hyperbaric environment of hydrospace. Although these procedures for fabricating the acrylic windows are somewhat involved, the results are extremely reliable. Acrylic viewports are now fabricated to very large sizes for manned observation or optical quality instrumen tation as illustrated by the numerous acrylic submersible vehicle hulls for hu, an occupancy currently in operation and a 3600 large optical window recently developed for the Walt Disney Circle Vision under-water camera housing.

  15. Viscoelastic behaviour of butyl acrylate/styrene/2-hydroxyethyl acrylate/acrylic acid latices thickened with associative thickneres

    Quadrat, Otakar; Mikešová, Jana; Horský, Jiří; Šňupárek, J.

    2003-01-01

    Roč. 6, 11-12 (2003), s. 1411-1416. ISSN 1631-0748 R&D Projects: GA ČR GA104/02/1360 Institutional research plan: CEZ:AV0Z4050913 Keywords : viscoelasticity * associative thickeners * latices Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.518, year: 2003

  16. FT-IR and FT-Raman studies of cross-linking processes with Ca²⁺ ions, glutaraldehyde and microwave radiation for polymer composition of poly(acrylic acid)/sodium salt of carboxymethyl starch - In moulding sands, Part II.

    Grabowska, Beata; Sitarz, Maciej; Olejnik, Ewa; Kaczmarska, Karolina; Tyliszczak, Bozena

    2015-12-01

    The hardening process of moulding sands on quartz matrices bound by polymer binders containing carboxyl and hydroxyl groups can be carried out by using physical (microwave radiation, thermal holding) and chemical (Ca(2+) cations, glutaraldehyde) cross-linking agents. The highest hardening level obtain moulding sand samples containing binders in a form of the aqueous composition of poly(acrylic acid)/sodium salt of carboxymethyl starch (PAA/CMS-Na) within the microwave radiation field, for which the bending strength is of 1.6 MPa value even after 24h from ending the agent activity. The authors focused, in this study, on finding the reason of this effect. It was shown, by means of the FT-IR and FT-Raman spectroscopic methods, that the chemical adsorption process activated by microwaves plays an essential role. The applied microwaves activate the polar groups present in the polymer composition structure as well as the quartz crystals surfaces (silane groups). Then the chemical adsorption occurs in the binder-matrix system within the microwave radiation field and intermolecular lattices are formed with a participation of hydrogen bridges (SiOH⋯OC, SiOH⋯OH) and COSi type bonds. PMID:26125981

  17. Humidity-constant Packaging Design Based on Spongy Polyurethane-poly(acrylic acid-acrylamide) Intelligent Material%基于多孔聚氨酯-聚丙烯酸/丙烯酰胺智能材料的恒湿包装设计

    万国顺; 赵志江; 武建斌; 黄红军

    2012-01-01

    以自制多孔聚氨酯-聚丙烯酸/丙烯酰胺(PU-PAA/AM)智能恒湿材料为基础,设计了一种具有防震缓冲和恒湿性能的包装材料,根据其吸湿量与吸湿时间、平衡含湿量与相对湿度的关系,提出了通过控制预吸湿时间来实现存储包装内环境湿度恒定的方法和公式。将防震缓冲和恒湿性能有机结合起来,在武器装备贮运包装领域具有很大的应用价值。%A package material integrating humidity constant property and buffer function together was designed based on self-made spongy polyurethane-poly(acrylic acid-acrylamide)(PU-PAA/AM) humidity constant intelligent material.The method and formula to realize constant humidity in packaging internal environment through control of pre-absorption time was put forward according to the relation between moisture content and pre-adsorption time,and equilibrium moisture content and relative humidity.The packaging material integrates buffer function and humidity constant property together,so it is can be widely used in weapons storage packaging and transportation.

  18. CORROSION INHIBITION OF CASSAVA STARCH GRAFT ACRYL AMIDE COPOLYMER FOR COLD ROLLED STEEL IN HYDROCHLORIC ACID%木薯淀粉接枝共聚物在盐酸介质中对冷轧钢的缓蚀作用

    付惠; 李向红; 李云仙; 刘建祥

    2011-01-01

    采用氧化还原引发体系引发木薯淀粉与丙烯酰胺接枝共聚反应制备的天然木薯淀粉接枝共聚物(SGA),可以作为一种环境友好型“绿色”缓蚀剂。本文用失重法、动电位极化曲线、电化学阻抗(EIS)和扫描电子显微镜(SEM)首次研究了SGA在1.0mol/LHCl溶液中对冷轧钢的缓蚀作用。结果表明,SGA对冷轧钢具有良好的缓蚀作用,在钢表面的吸附符合Langmuir吸附等温式,为混合抑制型缓蚀剂;EIS谱呈半圆容抗弧,电荷转移电阻随缓蚀剂浓度的增加而增大。SEM表明SGA在钢表面吸附形成了致密的缓蚀剂膜层。%Cassava starch graft acryl amide copolymer (SGA) was prepared by grafting acryl amide onto starch with oxidization reduction reaction, which can be used as a good environmentally-friendly "green" inhibitor. The inhibition effect of SGA on the corrosion of cold rolled steel (CRS) in 1.0 mol/L HCl has been studied by weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and scanning electron microscope (SEM) methods. The results show that SGA is a good inhibitor in 1.0 mol/L HC1 for CRS, and the adsorption of SGA on the CRS surface obeys Langmuir adsorption isotherm. Polarization curves show that SGA is a mixed-type inhibitor in hydrochloric acid. All EIS spectra exhibit one capacitive loop, and the charge transfer resistance increases with the inhibitor concentration. SEM results show that the introduction of SGA into HCl solution results in the formation of a compact and dense inhibitive film on the CRS surface.

  19. METHACRYLATE AND ACRYLATE ALLERGY IN DENTAL STUDENTS.

    Maya Lyapina

    2013-09-01

    Full Text Available A multitude of acrylic monomers is used in dentistry, and when dental personnel, patients or students of dental medicine become sensitized, it is of great importance to identify the dental ;acrylic preparations to which the sensitized individual can be exposed. Numerous studies confirm high incidence of sensitization to (meth acrylates in dentatal professionals, as well as in patients undergoing dental treatment and exposed to resin-based materials. Quite a few studies are available aiming to evaluate the incidence of sensitization in students of dental medicineThe purpose of the study is to evaluate the incidence of contact sensitization to some (meth acrylates in students of dental medicine at the time of their education, in dental professionals (dentists, nurses and attendants and in patients, the manifestation of co-reactivity.A total of 139 participants were included in the study, divided into four groups: occupationally exposed to (methacrylates and acrylic monomers dental professionals, 3-4 year-of-education students of dental medicine, 6th year–of-education students of dental medicine and patients with suspected or established sensitization to acrylates, without occupational exposure. All of them were patch-tested with methyl methacrylate (MMA, triethyleneglycol dimethacrylate (TREGDMA, ethyleneglycol dimethacrylate (EGDMA, 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy phenyl]propane (bis-GMA, 2-hydroxyethyl methacrylate (2-HEMA, and tetrahidrofurfuril metacrylate. The overall sensitization rates to methacrylates in the studied population are comparative high – from 25.9% for MMA to 31.7% for TREGDMA. Significantly higher incidence of sensitization in the group of 3-4 course students compared to the one in the group of dental professionals for MMA and TREGDMA was observed. Highest was the incidence of sensitization to ethyleneglycol dimethacrylate, BIS-GMA, 2-HEMA and tetrahydrofurfuryl methacrylate in the group of patients, with

  20. Effect of molecular weights and structures on properties of epoxidized palm oil acrylate (EPOLA) based radiation curable pressure sensitive adhesives (PSA)

    Three different types of EPOLAs were synthesised using epoxidized palm oil product (EPOP) and three different acid functional acrylate monomers (AFAMs) following the established acrylation procedures. The results were EPOLAs with three different MWs and structures. These EPOLAs were then formulated into PSA and the results were compared with each other. Higher MW and more branched AFAM produced higher MW EPOLA and consequently higher adhesive properties as compared to that of lower MW and more linear AFAM. (Author)